Perforating the masonry walls in rehabilitation of masonry Buildings using center core method Alireza Mahdizadeh - Jamaledin Borzouie Center core method is the good.

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Transcript Perforating the masonry walls in rehabilitation of masonry Buildings using center core method Alireza Mahdizadeh - Jamaledin Borzouie Center core method is the good.

Slide 1

Perforating the masonry walls in
rehabilitation of masonry
Buildings using center core method
Alireza Mahdizadeh - Jamaledin Borzouie

Center core method is the good suggestion for retrofitting of
Historical masonry buildings due to non-destructive
construction.

Importance of Historical Buildings
Cultural Importance
Economy of tourists

Economic Impacts

Life loss ( Historical schools)

Large cost of renovation
after earthquake

Arg-e-Bam and Bam earthquake,2003
The largest adobe building in the world
The origins of Bam : 6th to 4th centuries BC

Before Bam Earthquake,2003

After Bam Earthquake,2003

Time needed for rebuild of this structure after damage of Bam earthquake :12 years
Total cost for rebuild : 120 million $

Before Bam Earthquake,2003

After Bam Earthquake,2003

Solution

Why Center core?
others
1%

concrete
2%
steel
8%

Large number of
masonry buildings
Masonry
89%

Non-destructive method

Without Evacuation

Steps

Problems

Perforating the
masonry walls

How to perforate masonry walls
without any cracks on wall
surface

Placing bars in
holes

Area, Distance, Number of bars

Placing grout
in holes

Properties of grout

the building was studied under the critical conditions
Very weak mortar

Strong bricks

Loose finishing of the wall
Wall thickness is at most
30 centimetres
selected school: Do Shahid
The building has 3 The
stories
Aged about 50 years

Parts of Drilling systems
Drilling Machine

Rod

Hydraulic

Rotary

Drilling
Rod transmits
machinethe
produces
rotatingthe
force
energy
to the stabilizer
for rotation
and
ofbit
the bit

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer
Stabilizer reduces the lateral movements
and bit shaking along the drilling path

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer

Bits

Bit penetrates through the depth and
determines the drilling path

Principle of design
4 boreholes (total 28 m height) were perforated in this project.
In each borehole, drilling technique, equipments and bits were
changed or design according to the damage in the wall surface .
After observation of these cracks the wall surface was
destructed; moreover, a new bit or stabilizer was designed
according to movement of bit on surface of bricks and other
observations ( air pressure, rotation of bit ...) to obtain the most
suitable ones.

Step 1: changing available Bits and Stabilizers
in drilling to obtain general vision for next step
Bit properties

Diamond
Non coring
D: 76 mm
Diamond
Coring
D: 76 mm

TC
Coring
D: 93mm

picture

Damage
Bit deviation due to large
contact surface with cement

How we deal with this
new
Cracks were observed In the
part of the wall due
problem? weakest
to high air pressure and lack
of mortar in the gap between
two bricks, the air flow pushes
the finishing and damages it
such that cuttings were
dispersed.

Bit properties

TC
Non coring
D: 93 mm

picture

Damage

Cracks appear due to weak
bricking

Good Suggestion for next step
TC
Non coring
D: 66mm

Finishing remains unhurt

Step 2: Designing new bits and stabilizers by
result of past drillings

TC
Non coring
D: 76 mm
TC 6 mm×6mm

New changes:
Increaseof TC dimension: 6 mm×6mm

New ways for exist of cuttings

Step 2: Designing new bits and stabilizers by
result of past drillings

Increase
dimension of
cuttings

A Cutting act
as a base

Spiral motion
of drilling
system

Crack in wall
surface

To prevent spiral motion and lateral motion Special
stabilization was designed

These holes were considered for escape of cuttings
Adding this type of stabilization decrease lateral movement; however, these holes
do not supply enough area for escape of cuttings

……Other bits and a stabilizer were designed and
cracks that appeared in each step led to
development of final drilling system and technical
drilling….

Final Bit

Final Bit

Final Bit

Final Bit

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

How the new designed bit act?

Masonry Wall

Rod

Escape line
Of cuttings
Masonry Wall

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

Conclusion
1. Rate of penetration with non-coring bits is high. However, these bits
are not as precise as coring bits. In spite of high precision coring bits
are not so fast due to several pull out of the bits for emptying the
cores.
2. If non-coring bits are used, as the size of TCs increases, the
deviation of the hole will increase. Larger cuttings lead to asymmetric
engagement of TC and cuttings and make a permanent change in the
axis of rotation.

Conclusion
3. Stabilizers are used to increase the accuracy and decrease the
deviation in drilling path. Although, it must be noted that they
increase air pressure on the surface of the holes and crack the
finishing.
4. The most important result of this study is the combination of coring
and non-coring bits. To stabilize the drilling path and decrease the
deviation, a guide is installed on the TC-Non-Coring bit instead of
stabilizers. On the whole, this drilling bit contains a TC Coring bit
which cores from the masonry walls. This bit penetrates through the
wall as a guide and prevents the bit from deviation and out of axis
rotation. In a short distance from the TC-Coring bit, TC Non-Coring bit
is installed. This bit crushes the cores and makes the cuttings ready for
being removed from the hole as dust. The smaller the cuttings are, the
lower air pressure is needed to remove them.

Conclusion
5. This newly invented bit could use for mining, oil and other
excavations as well.
6. Hydraulic drilling machines have a better performance
compared to SGZ Rotary machine because they are larger.
7. The drilling technique must be such that the bit pressure would
be minimum.

Conclusion
8. The brick type, mortar and the quality of bricking are
determining factors for setting the drilling speed and air pressure.
It seems that we can’t have exact quantities of such factors now;
however, an expert drilling operator may achieve this.

9. During drilling operation, the speed of rotation and air pressure
could be set by observing the size of cuttings. An expert can
minimize the size of cuttings by paying attention to it.

Thanks for your kind Attention


Slide 2

Perforating the masonry walls in
rehabilitation of masonry
Buildings using center core method
Alireza Mahdizadeh - Jamaledin Borzouie

Center core method is the good suggestion for retrofitting of
Historical masonry buildings due to non-destructive
construction.

Importance of Historical Buildings
Cultural Importance
Economy of tourists

Economic Impacts

Life loss ( Historical schools)

Large cost of renovation
after earthquake

Arg-e-Bam and Bam earthquake,2003
The largest adobe building in the world
The origins of Bam : 6th to 4th centuries BC

Before Bam Earthquake,2003

After Bam Earthquake,2003

Time needed for rebuild of this structure after damage of Bam earthquake :12 years
Total cost for rebuild : 120 million $

Before Bam Earthquake,2003

After Bam Earthquake,2003

Solution

Why Center core?
others
1%

concrete
2%
steel
8%

Large number of
masonry buildings
Masonry
89%

Non-destructive method

Without Evacuation

Steps

Problems

Perforating the
masonry walls

How to perforate masonry walls
without any cracks on wall
surface

Placing bars in
holes

Area, Distance, Number of bars

Placing grout
in holes

Properties of grout

the building was studied under the critical conditions
Very weak mortar

Strong bricks

Loose finishing of the wall
Wall thickness is at most
30 centimetres
selected school: Do Shahid
The building has 3 The
stories
Aged about 50 years

Parts of Drilling systems
Drilling Machine

Rod

Hydraulic

Rotary

Drilling
Rod transmits
machinethe
produces
rotatingthe
force
energy
to the stabilizer
for rotation
and
ofbit
the bit

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer
Stabilizer reduces the lateral movements
and bit shaking along the drilling path

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer

Bits

Bit penetrates through the depth and
determines the drilling path

Principle of design
4 boreholes (total 28 m height) were perforated in this project.
In each borehole, drilling technique, equipments and bits were
changed or design according to the damage in the wall surface .
After observation of these cracks the wall surface was
destructed; moreover, a new bit or stabilizer was designed
according to movement of bit on surface of bricks and other
observations ( air pressure, rotation of bit ...) to obtain the most
suitable ones.

Step 1: changing available Bits and Stabilizers
in drilling to obtain general vision for next step
Bit properties

Diamond
Non coring
D: 76 mm
Diamond
Coring
D: 76 mm

TC
Coring
D: 93mm

picture

Damage
Bit deviation due to large
contact surface with cement

How we deal with this
new
Cracks were observed In the
part of the wall due
problem? weakest
to high air pressure and lack
of mortar in the gap between
two bricks, the air flow pushes
the finishing and damages it
such that cuttings were
dispersed.

Bit properties

TC
Non coring
D: 93 mm

picture

Damage

Cracks appear due to weak
bricking

Good Suggestion for next step
TC
Non coring
D: 66mm

Finishing remains unhurt

Step 2: Designing new bits and stabilizers by
result of past drillings

TC
Non coring
D: 76 mm
TC 6 mm×6mm

New changes:
Increaseof TC dimension: 6 mm×6mm

New ways for exist of cuttings

Step 2: Designing new bits and stabilizers by
result of past drillings

Increase
dimension of
cuttings

A Cutting act
as a base

Spiral motion
of drilling
system

Crack in wall
surface

To prevent spiral motion and lateral motion Special
stabilization was designed

These holes were considered for escape of cuttings
Adding this type of stabilization decrease lateral movement; however, these holes
do not supply enough area for escape of cuttings

……Other bits and a stabilizer were designed and
cracks that appeared in each step led to
development of final drilling system and technical
drilling….

Final Bit

Final Bit

Final Bit

Final Bit

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

How the new designed bit act?

Masonry Wall

Rod

Escape line
Of cuttings
Masonry Wall

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

Conclusion
1. Rate of penetration with non-coring bits is high. However, these bits
are not as precise as coring bits. In spite of high precision coring bits
are not so fast due to several pull out of the bits for emptying the
cores.
2. If non-coring bits are used, as the size of TCs increases, the
deviation of the hole will increase. Larger cuttings lead to asymmetric
engagement of TC and cuttings and make a permanent change in the
axis of rotation.

Conclusion
3. Stabilizers are used to increase the accuracy and decrease the
deviation in drilling path. Although, it must be noted that they
increase air pressure on the surface of the holes and crack the
finishing.
4. The most important result of this study is the combination of coring
and non-coring bits. To stabilize the drilling path and decrease the
deviation, a guide is installed on the TC-Non-Coring bit instead of
stabilizers. On the whole, this drilling bit contains a TC Coring bit
which cores from the masonry walls. This bit penetrates through the
wall as a guide and prevents the bit from deviation and out of axis
rotation. In a short distance from the TC-Coring bit, TC Non-Coring bit
is installed. This bit crushes the cores and makes the cuttings ready for
being removed from the hole as dust. The smaller the cuttings are, the
lower air pressure is needed to remove them.

Conclusion
5. This newly invented bit could use for mining, oil and other
excavations as well.
6. Hydraulic drilling machines have a better performance
compared to SGZ Rotary machine because they are larger.
7. The drilling technique must be such that the bit pressure would
be minimum.

Conclusion
8. The brick type, mortar and the quality of bricking are
determining factors for setting the drilling speed and air pressure.
It seems that we can’t have exact quantities of such factors now;
however, an expert drilling operator may achieve this.

9. During drilling operation, the speed of rotation and air pressure
could be set by observing the size of cuttings. An expert can
minimize the size of cuttings by paying attention to it.

Thanks for your kind Attention


Slide 3

Perforating the masonry walls in
rehabilitation of masonry
Buildings using center core method
Alireza Mahdizadeh - Jamaledin Borzouie

Center core method is the good suggestion for retrofitting of
Historical masonry buildings due to non-destructive
construction.

Importance of Historical Buildings
Cultural Importance
Economy of tourists

Economic Impacts

Life loss ( Historical schools)

Large cost of renovation
after earthquake

Arg-e-Bam and Bam earthquake,2003
The largest adobe building in the world
The origins of Bam : 6th to 4th centuries BC

Before Bam Earthquake,2003

After Bam Earthquake,2003

Time needed for rebuild of this structure after damage of Bam earthquake :12 years
Total cost for rebuild : 120 million $

Before Bam Earthquake,2003

After Bam Earthquake,2003

Solution

Why Center core?
others
1%

concrete
2%
steel
8%

Large number of
masonry buildings
Masonry
89%

Non-destructive method

Without Evacuation

Steps

Problems

Perforating the
masonry walls

How to perforate masonry walls
without any cracks on wall
surface

Placing bars in
holes

Area, Distance, Number of bars

Placing grout
in holes

Properties of grout

the building was studied under the critical conditions
Very weak mortar

Strong bricks

Loose finishing of the wall
Wall thickness is at most
30 centimetres
selected school: Do Shahid
The building has 3 The
stories
Aged about 50 years

Parts of Drilling systems
Drilling Machine

Rod

Hydraulic

Rotary

Drilling
Rod transmits
machinethe
produces
rotatingthe
force
energy
to the stabilizer
for rotation
and
ofbit
the bit

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer
Stabilizer reduces the lateral movements
and bit shaking along the drilling path

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer

Bits

Bit penetrates through the depth and
determines the drilling path

Principle of design
4 boreholes (total 28 m height) were perforated in this project.
In each borehole, drilling technique, equipments and bits were
changed or design according to the damage in the wall surface .
After observation of these cracks the wall surface was
destructed; moreover, a new bit or stabilizer was designed
according to movement of bit on surface of bricks and other
observations ( air pressure, rotation of bit ...) to obtain the most
suitable ones.

Step 1: changing available Bits and Stabilizers
in drilling to obtain general vision for next step
Bit properties

Diamond
Non coring
D: 76 mm
Diamond
Coring
D: 76 mm

TC
Coring
D: 93mm

picture

Damage
Bit deviation due to large
contact surface with cement

How we deal with this
new
Cracks were observed In the
part of the wall due
problem? weakest
to high air pressure and lack
of mortar in the gap between
two bricks, the air flow pushes
the finishing and damages it
such that cuttings were
dispersed.

Bit properties

TC
Non coring
D: 93 mm

picture

Damage

Cracks appear due to weak
bricking

Good Suggestion for next step
TC
Non coring
D: 66mm

Finishing remains unhurt

Step 2: Designing new bits and stabilizers by
result of past drillings

TC
Non coring
D: 76 mm
TC 6 mm×6mm

New changes:
Increaseof TC dimension: 6 mm×6mm

New ways for exist of cuttings

Step 2: Designing new bits and stabilizers by
result of past drillings

Increase
dimension of
cuttings

A Cutting act
as a base

Spiral motion
of drilling
system

Crack in wall
surface

To prevent spiral motion and lateral motion Special
stabilization was designed

These holes were considered for escape of cuttings
Adding this type of stabilization decrease lateral movement; however, these holes
do not supply enough area for escape of cuttings

……Other bits and a stabilizer were designed and
cracks that appeared in each step led to
development of final drilling system and technical
drilling….

Final Bit

Final Bit

Final Bit

Final Bit

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

How the new designed bit act?

Masonry Wall

Rod

Escape line
Of cuttings
Masonry Wall

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

Conclusion
1. Rate of penetration with non-coring bits is high. However, these bits
are not as precise as coring bits. In spite of high precision coring bits
are not so fast due to several pull out of the bits for emptying the
cores.
2. If non-coring bits are used, as the size of TCs increases, the
deviation of the hole will increase. Larger cuttings lead to asymmetric
engagement of TC and cuttings and make a permanent change in the
axis of rotation.

Conclusion
3. Stabilizers are used to increase the accuracy and decrease the
deviation in drilling path. Although, it must be noted that they
increase air pressure on the surface of the holes and crack the
finishing.
4. The most important result of this study is the combination of coring
and non-coring bits. To stabilize the drilling path and decrease the
deviation, a guide is installed on the TC-Non-Coring bit instead of
stabilizers. On the whole, this drilling bit contains a TC Coring bit
which cores from the masonry walls. This bit penetrates through the
wall as a guide and prevents the bit from deviation and out of axis
rotation. In a short distance from the TC-Coring bit, TC Non-Coring bit
is installed. This bit crushes the cores and makes the cuttings ready for
being removed from the hole as dust. The smaller the cuttings are, the
lower air pressure is needed to remove them.

Conclusion
5. This newly invented bit could use for mining, oil and other
excavations as well.
6. Hydraulic drilling machines have a better performance
compared to SGZ Rotary machine because they are larger.
7. The drilling technique must be such that the bit pressure would
be minimum.

Conclusion
8. The brick type, mortar and the quality of bricking are
determining factors for setting the drilling speed and air pressure.
It seems that we can’t have exact quantities of such factors now;
however, an expert drilling operator may achieve this.

9. During drilling operation, the speed of rotation and air pressure
could be set by observing the size of cuttings. An expert can
minimize the size of cuttings by paying attention to it.

Thanks for your kind Attention


Slide 4

Perforating the masonry walls in
rehabilitation of masonry
Buildings using center core method
Alireza Mahdizadeh - Jamaledin Borzouie

Center core method is the good suggestion for retrofitting of
Historical masonry buildings due to non-destructive
construction.

Importance of Historical Buildings
Cultural Importance
Economy of tourists

Economic Impacts

Life loss ( Historical schools)

Large cost of renovation
after earthquake

Arg-e-Bam and Bam earthquake,2003
The largest adobe building in the world
The origins of Bam : 6th to 4th centuries BC

Before Bam Earthquake,2003

After Bam Earthquake,2003

Time needed for rebuild of this structure after damage of Bam earthquake :12 years
Total cost for rebuild : 120 million $

Before Bam Earthquake,2003

After Bam Earthquake,2003

Solution

Why Center core?
others
1%

concrete
2%
steel
8%

Large number of
masonry buildings
Masonry
89%

Non-destructive method

Without Evacuation

Steps

Problems

Perforating the
masonry walls

How to perforate masonry walls
without any cracks on wall
surface

Placing bars in
holes

Area, Distance, Number of bars

Placing grout
in holes

Properties of grout

the building was studied under the critical conditions
Very weak mortar

Strong bricks

Loose finishing of the wall
Wall thickness is at most
30 centimetres
selected school: Do Shahid
The building has 3 The
stories
Aged about 50 years

Parts of Drilling systems
Drilling Machine

Rod

Hydraulic

Rotary

Drilling
Rod transmits
machinethe
produces
rotatingthe
force
energy
to the stabilizer
for rotation
and
ofbit
the bit

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer
Stabilizer reduces the lateral movements
and bit shaking along the drilling path

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer

Bits

Bit penetrates through the depth and
determines the drilling path

Principle of design
4 boreholes (total 28 m height) were perforated in this project.
In each borehole, drilling technique, equipments and bits were
changed or design according to the damage in the wall surface .
After observation of these cracks the wall surface was
destructed; moreover, a new bit or stabilizer was designed
according to movement of bit on surface of bricks and other
observations ( air pressure, rotation of bit ...) to obtain the most
suitable ones.

Step 1: changing available Bits and Stabilizers
in drilling to obtain general vision for next step
Bit properties

Diamond
Non coring
D: 76 mm
Diamond
Coring
D: 76 mm

TC
Coring
D: 93mm

picture

Damage
Bit deviation due to large
contact surface with cement

How we deal with this
new
Cracks were observed In the
part of the wall due
problem? weakest
to high air pressure and lack
of mortar in the gap between
two bricks, the air flow pushes
the finishing and damages it
such that cuttings were
dispersed.

Bit properties

TC
Non coring
D: 93 mm

picture

Damage

Cracks appear due to weak
bricking

Good Suggestion for next step
TC
Non coring
D: 66mm

Finishing remains unhurt

Step 2: Designing new bits and stabilizers by
result of past drillings

TC
Non coring
D: 76 mm
TC 6 mm×6mm

New changes:
Increaseof TC dimension: 6 mm×6mm

New ways for exist of cuttings

Step 2: Designing new bits and stabilizers by
result of past drillings

Increase
dimension of
cuttings

A Cutting act
as a base

Spiral motion
of drilling
system

Crack in wall
surface

To prevent spiral motion and lateral motion Special
stabilization was designed

These holes were considered for escape of cuttings
Adding this type of stabilization decrease lateral movement; however, these holes
do not supply enough area for escape of cuttings

……Other bits and a stabilizer were designed and
cracks that appeared in each step led to
development of final drilling system and technical
drilling….

Final Bit

Final Bit

Final Bit

Final Bit

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

How the new designed bit act?

Masonry Wall

Rod

Escape line
Of cuttings
Masonry Wall

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

Conclusion
1. Rate of penetration with non-coring bits is high. However, these bits
are not as precise as coring bits. In spite of high precision coring bits
are not so fast due to several pull out of the bits for emptying the
cores.
2. If non-coring bits are used, as the size of TCs increases, the
deviation of the hole will increase. Larger cuttings lead to asymmetric
engagement of TC and cuttings and make a permanent change in the
axis of rotation.

Conclusion
3. Stabilizers are used to increase the accuracy and decrease the
deviation in drilling path. Although, it must be noted that they
increase air pressure on the surface of the holes and crack the
finishing.
4. The most important result of this study is the combination of coring
and non-coring bits. To stabilize the drilling path and decrease the
deviation, a guide is installed on the TC-Non-Coring bit instead of
stabilizers. On the whole, this drilling bit contains a TC Coring bit
which cores from the masonry walls. This bit penetrates through the
wall as a guide and prevents the bit from deviation and out of axis
rotation. In a short distance from the TC-Coring bit, TC Non-Coring bit
is installed. This bit crushes the cores and makes the cuttings ready for
being removed from the hole as dust. The smaller the cuttings are, the
lower air pressure is needed to remove them.

Conclusion
5. This newly invented bit could use for mining, oil and other
excavations as well.
6. Hydraulic drilling machines have a better performance
compared to SGZ Rotary machine because they are larger.
7. The drilling technique must be such that the bit pressure would
be minimum.

Conclusion
8. The brick type, mortar and the quality of bricking are
determining factors for setting the drilling speed and air pressure.
It seems that we can’t have exact quantities of such factors now;
however, an expert drilling operator may achieve this.

9. During drilling operation, the speed of rotation and air pressure
could be set by observing the size of cuttings. An expert can
minimize the size of cuttings by paying attention to it.

Thanks for your kind Attention


Slide 5

Perforating the masonry walls in
rehabilitation of masonry
Buildings using center core method
Alireza Mahdizadeh - Jamaledin Borzouie

Center core method is the good suggestion for retrofitting of
Historical masonry buildings due to non-destructive
construction.

Importance of Historical Buildings
Cultural Importance
Economy of tourists

Economic Impacts

Life loss ( Historical schools)

Large cost of renovation
after earthquake

Arg-e-Bam and Bam earthquake,2003
The largest adobe building in the world
The origins of Bam : 6th to 4th centuries BC

Before Bam Earthquake,2003

After Bam Earthquake,2003

Time needed for rebuild of this structure after damage of Bam earthquake :12 years
Total cost for rebuild : 120 million $

Before Bam Earthquake,2003

After Bam Earthquake,2003

Solution

Why Center core?
others
1%

concrete
2%
steel
8%

Large number of
masonry buildings
Masonry
89%

Non-destructive method

Without Evacuation

Steps

Problems

Perforating the
masonry walls

How to perforate masonry walls
without any cracks on wall
surface

Placing bars in
holes

Area, Distance, Number of bars

Placing grout
in holes

Properties of grout

the building was studied under the critical conditions
Very weak mortar

Strong bricks

Loose finishing of the wall
Wall thickness is at most
30 centimetres
selected school: Do Shahid
The building has 3 The
stories
Aged about 50 years

Parts of Drilling systems
Drilling Machine

Rod

Hydraulic

Rotary

Drilling
Rod transmits
machinethe
produces
rotatingthe
force
energy
to the stabilizer
for rotation
and
ofbit
the bit

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer
Stabilizer reduces the lateral movements
and bit shaking along the drilling path

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer

Bits

Bit penetrates through the depth and
determines the drilling path

Principle of design
4 boreholes (total 28 m height) were perforated in this project.
In each borehole, drilling technique, equipments and bits were
changed or design according to the damage in the wall surface .
After observation of these cracks the wall surface was
destructed; moreover, a new bit or stabilizer was designed
according to movement of bit on surface of bricks and other
observations ( air pressure, rotation of bit ...) to obtain the most
suitable ones.

Step 1: changing available Bits and Stabilizers
in drilling to obtain general vision for next step
Bit properties

Diamond
Non coring
D: 76 mm
Diamond
Coring
D: 76 mm

TC
Coring
D: 93mm

picture

Damage
Bit deviation due to large
contact surface with cement

How we deal with this
new
Cracks were observed In the
part of the wall due
problem? weakest
to high air pressure and lack
of mortar in the gap between
two bricks, the air flow pushes
the finishing and damages it
such that cuttings were
dispersed.

Bit properties

TC
Non coring
D: 93 mm

picture

Damage

Cracks appear due to weak
bricking

Good Suggestion for next step
TC
Non coring
D: 66mm

Finishing remains unhurt

Step 2: Designing new bits and stabilizers by
result of past drillings

TC
Non coring
D: 76 mm
TC 6 mm×6mm

New changes:
Increaseof TC dimension: 6 mm×6mm

New ways for exist of cuttings

Step 2: Designing new bits and stabilizers by
result of past drillings

Increase
dimension of
cuttings

A Cutting act
as a base

Spiral motion
of drilling
system

Crack in wall
surface

To prevent spiral motion and lateral motion Special
stabilization was designed

These holes were considered for escape of cuttings
Adding this type of stabilization decrease lateral movement; however, these holes
do not supply enough area for escape of cuttings

……Other bits and a stabilizer were designed and
cracks that appeared in each step led to
development of final drilling system and technical
drilling….

Final Bit

Final Bit

Final Bit

Final Bit

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

How the new designed bit act?

Masonry Wall

Rod

Escape line
Of cuttings
Masonry Wall

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

Conclusion
1. Rate of penetration with non-coring bits is high. However, these bits
are not as precise as coring bits. In spite of high precision coring bits
are not so fast due to several pull out of the bits for emptying the
cores.
2. If non-coring bits are used, as the size of TCs increases, the
deviation of the hole will increase. Larger cuttings lead to asymmetric
engagement of TC and cuttings and make a permanent change in the
axis of rotation.

Conclusion
3. Stabilizers are used to increase the accuracy and decrease the
deviation in drilling path. Although, it must be noted that they
increase air pressure on the surface of the holes and crack the
finishing.
4. The most important result of this study is the combination of coring
and non-coring bits. To stabilize the drilling path and decrease the
deviation, a guide is installed on the TC-Non-Coring bit instead of
stabilizers. On the whole, this drilling bit contains a TC Coring bit
which cores from the masonry walls. This bit penetrates through the
wall as a guide and prevents the bit from deviation and out of axis
rotation. In a short distance from the TC-Coring bit, TC Non-Coring bit
is installed. This bit crushes the cores and makes the cuttings ready for
being removed from the hole as dust. The smaller the cuttings are, the
lower air pressure is needed to remove them.

Conclusion
5. This newly invented bit could use for mining, oil and other
excavations as well.
6. Hydraulic drilling machines have a better performance
compared to SGZ Rotary machine because they are larger.
7. The drilling technique must be such that the bit pressure would
be minimum.

Conclusion
8. The brick type, mortar and the quality of bricking are
determining factors for setting the drilling speed and air pressure.
It seems that we can’t have exact quantities of such factors now;
however, an expert drilling operator may achieve this.

9. During drilling operation, the speed of rotation and air pressure
could be set by observing the size of cuttings. An expert can
minimize the size of cuttings by paying attention to it.

Thanks for your kind Attention


Slide 6

Perforating the masonry walls in
rehabilitation of masonry
Buildings using center core method
Alireza Mahdizadeh - Jamaledin Borzouie

Center core method is the good suggestion for retrofitting of
Historical masonry buildings due to non-destructive
construction.

Importance of Historical Buildings
Cultural Importance
Economy of tourists

Economic Impacts

Life loss ( Historical schools)

Large cost of renovation
after earthquake

Arg-e-Bam and Bam earthquake,2003
The largest adobe building in the world
The origins of Bam : 6th to 4th centuries BC

Before Bam Earthquake,2003

After Bam Earthquake,2003

Time needed for rebuild of this structure after damage of Bam earthquake :12 years
Total cost for rebuild : 120 million $

Before Bam Earthquake,2003

After Bam Earthquake,2003

Solution

Why Center core?
others
1%

concrete
2%
steel
8%

Large number of
masonry buildings
Masonry
89%

Non-destructive method

Without Evacuation

Steps

Problems

Perforating the
masonry walls

How to perforate masonry walls
without any cracks on wall
surface

Placing bars in
holes

Area, Distance, Number of bars

Placing grout
in holes

Properties of grout

the building was studied under the critical conditions
Very weak mortar

Strong bricks

Loose finishing of the wall
Wall thickness is at most
30 centimetres
selected school: Do Shahid
The building has 3 The
stories
Aged about 50 years

Parts of Drilling systems
Drilling Machine

Rod

Hydraulic

Rotary

Drilling
Rod transmits
machinethe
produces
rotatingthe
force
energy
to the stabilizer
for rotation
and
ofbit
the bit

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer
Stabilizer reduces the lateral movements
and bit shaking along the drilling path

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer

Bits

Bit penetrates through the depth and
determines the drilling path

Principle of design
4 boreholes (total 28 m height) were perforated in this project.
In each borehole, drilling technique, equipments and bits were
changed or design according to the damage in the wall surface .
After observation of these cracks the wall surface was
destructed; moreover, a new bit or stabilizer was designed
according to movement of bit on surface of bricks and other
observations ( air pressure, rotation of bit ...) to obtain the most
suitable ones.

Step 1: changing available Bits and Stabilizers
in drilling to obtain general vision for next step
Bit properties

Diamond
Non coring
D: 76 mm
Diamond
Coring
D: 76 mm

TC
Coring
D: 93mm

picture

Damage
Bit deviation due to large
contact surface with cement

How we deal with this
new
Cracks were observed In the
part of the wall due
problem? weakest
to high air pressure and lack
of mortar in the gap between
two bricks, the air flow pushes
the finishing and damages it
such that cuttings were
dispersed.

Bit properties

TC
Non coring
D: 93 mm

picture

Damage

Cracks appear due to weak
bricking

Good Suggestion for next step
TC
Non coring
D: 66mm

Finishing remains unhurt

Step 2: Designing new bits and stabilizers by
result of past drillings

TC
Non coring
D: 76 mm
TC 6 mm×6mm

New changes:
Increaseof TC dimension: 6 mm×6mm

New ways for exist of cuttings

Step 2: Designing new bits and stabilizers by
result of past drillings

Increase
dimension of
cuttings

A Cutting act
as a base

Spiral motion
of drilling
system

Crack in wall
surface

To prevent spiral motion and lateral motion Special
stabilization was designed

These holes were considered for escape of cuttings
Adding this type of stabilization decrease lateral movement; however, these holes
do not supply enough area for escape of cuttings

……Other bits and a stabilizer were designed and
cracks that appeared in each step led to
development of final drilling system and technical
drilling….

Final Bit

Final Bit

Final Bit

Final Bit

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

How the new designed bit act?

Masonry Wall

Rod

Escape line
Of cuttings
Masonry Wall

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

Conclusion
1. Rate of penetration with non-coring bits is high. However, these bits
are not as precise as coring bits. In spite of high precision coring bits
are not so fast due to several pull out of the bits for emptying the
cores.
2. If non-coring bits are used, as the size of TCs increases, the
deviation of the hole will increase. Larger cuttings lead to asymmetric
engagement of TC and cuttings and make a permanent change in the
axis of rotation.

Conclusion
3. Stabilizers are used to increase the accuracy and decrease the
deviation in drilling path. Although, it must be noted that they
increase air pressure on the surface of the holes and crack the
finishing.
4. The most important result of this study is the combination of coring
and non-coring bits. To stabilize the drilling path and decrease the
deviation, a guide is installed on the TC-Non-Coring bit instead of
stabilizers. On the whole, this drilling bit contains a TC Coring bit
which cores from the masonry walls. This bit penetrates through the
wall as a guide and prevents the bit from deviation and out of axis
rotation. In a short distance from the TC-Coring bit, TC Non-Coring bit
is installed. This bit crushes the cores and makes the cuttings ready for
being removed from the hole as dust. The smaller the cuttings are, the
lower air pressure is needed to remove them.

Conclusion
5. This newly invented bit could use for mining, oil and other
excavations as well.
6. Hydraulic drilling machines have a better performance
compared to SGZ Rotary machine because they are larger.
7. The drilling technique must be such that the bit pressure would
be minimum.

Conclusion
8. The brick type, mortar and the quality of bricking are
determining factors for setting the drilling speed and air pressure.
It seems that we can’t have exact quantities of such factors now;
however, an expert drilling operator may achieve this.

9. During drilling operation, the speed of rotation and air pressure
could be set by observing the size of cuttings. An expert can
minimize the size of cuttings by paying attention to it.

Thanks for your kind Attention


Slide 7

Perforating the masonry walls in
rehabilitation of masonry
Buildings using center core method
Alireza Mahdizadeh - Jamaledin Borzouie

Center core method is the good suggestion for retrofitting of
Historical masonry buildings due to non-destructive
construction.

Importance of Historical Buildings
Cultural Importance
Economy of tourists

Economic Impacts

Life loss ( Historical schools)

Large cost of renovation
after earthquake

Arg-e-Bam and Bam earthquake,2003
The largest adobe building in the world
The origins of Bam : 6th to 4th centuries BC

Before Bam Earthquake,2003

After Bam Earthquake,2003

Time needed for rebuild of this structure after damage of Bam earthquake :12 years
Total cost for rebuild : 120 million $

Before Bam Earthquake,2003

After Bam Earthquake,2003

Solution

Why Center core?
others
1%

concrete
2%
steel
8%

Large number of
masonry buildings
Masonry
89%

Non-destructive method

Without Evacuation

Steps

Problems

Perforating the
masonry walls

How to perforate masonry walls
without any cracks on wall
surface

Placing bars in
holes

Area, Distance, Number of bars

Placing grout
in holes

Properties of grout

the building was studied under the critical conditions
Very weak mortar

Strong bricks

Loose finishing of the wall
Wall thickness is at most
30 centimetres
selected school: Do Shahid
The building has 3 The
stories
Aged about 50 years

Parts of Drilling systems
Drilling Machine

Rod

Hydraulic

Rotary

Drilling
Rod transmits
machinethe
produces
rotatingthe
force
energy
to the stabilizer
for rotation
and
ofbit
the bit

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer
Stabilizer reduces the lateral movements
and bit shaking along the drilling path

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer

Bits

Bit penetrates through the depth and
determines the drilling path

Principle of design
4 boreholes (total 28 m height) were perforated in this project.
In each borehole, drilling technique, equipments and bits were
changed or design according to the damage in the wall surface .
After observation of these cracks the wall surface was
destructed; moreover, a new bit or stabilizer was designed
according to movement of bit on surface of bricks and other
observations ( air pressure, rotation of bit ...) to obtain the most
suitable ones.

Step 1: changing available Bits and Stabilizers
in drilling to obtain general vision for next step
Bit properties

Diamond
Non coring
D: 76 mm
Diamond
Coring
D: 76 mm

TC
Coring
D: 93mm

picture

Damage
Bit deviation due to large
contact surface with cement

How we deal with this
new
Cracks were observed In the
part of the wall due
problem? weakest
to high air pressure and lack
of mortar in the gap between
two bricks, the air flow pushes
the finishing and damages it
such that cuttings were
dispersed.

Bit properties

TC
Non coring
D: 93 mm

picture

Damage

Cracks appear due to weak
bricking

Good Suggestion for next step
TC
Non coring
D: 66mm

Finishing remains unhurt

Step 2: Designing new bits and stabilizers by
result of past drillings

TC
Non coring
D: 76 mm
TC 6 mm×6mm

New changes:
Increaseof TC dimension: 6 mm×6mm

New ways for exist of cuttings

Step 2: Designing new bits and stabilizers by
result of past drillings

Increase
dimension of
cuttings

A Cutting act
as a base

Spiral motion
of drilling
system

Crack in wall
surface

To prevent spiral motion and lateral motion Special
stabilization was designed

These holes were considered for escape of cuttings
Adding this type of stabilization decrease lateral movement; however, these holes
do not supply enough area for escape of cuttings

……Other bits and a stabilizer were designed and
cracks that appeared in each step led to
development of final drilling system and technical
drilling….

Final Bit

Final Bit

Final Bit

Final Bit

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

How the new designed bit act?

Masonry Wall

Rod

Escape line
Of cuttings
Masonry Wall

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

Conclusion
1. Rate of penetration with non-coring bits is high. However, these bits
are not as precise as coring bits. In spite of high precision coring bits
are not so fast due to several pull out of the bits for emptying the
cores.
2. If non-coring bits are used, as the size of TCs increases, the
deviation of the hole will increase. Larger cuttings lead to asymmetric
engagement of TC and cuttings and make a permanent change in the
axis of rotation.

Conclusion
3. Stabilizers are used to increase the accuracy and decrease the
deviation in drilling path. Although, it must be noted that they
increase air pressure on the surface of the holes and crack the
finishing.
4. The most important result of this study is the combination of coring
and non-coring bits. To stabilize the drilling path and decrease the
deviation, a guide is installed on the TC-Non-Coring bit instead of
stabilizers. On the whole, this drilling bit contains a TC Coring bit
which cores from the masonry walls. This bit penetrates through the
wall as a guide and prevents the bit from deviation and out of axis
rotation. In a short distance from the TC-Coring bit, TC Non-Coring bit
is installed. This bit crushes the cores and makes the cuttings ready for
being removed from the hole as dust. The smaller the cuttings are, the
lower air pressure is needed to remove them.

Conclusion
5. This newly invented bit could use for mining, oil and other
excavations as well.
6. Hydraulic drilling machines have a better performance
compared to SGZ Rotary machine because they are larger.
7. The drilling technique must be such that the bit pressure would
be minimum.

Conclusion
8. The brick type, mortar and the quality of bricking are
determining factors for setting the drilling speed and air pressure.
It seems that we can’t have exact quantities of such factors now;
however, an expert drilling operator may achieve this.

9. During drilling operation, the speed of rotation and air pressure
could be set by observing the size of cuttings. An expert can
minimize the size of cuttings by paying attention to it.

Thanks for your kind Attention


Slide 8

Perforating the masonry walls in
rehabilitation of masonry
Buildings using center core method
Alireza Mahdizadeh - Jamaledin Borzouie

Center core method is the good suggestion for retrofitting of
Historical masonry buildings due to non-destructive
construction.

Importance of Historical Buildings
Cultural Importance
Economy of tourists

Economic Impacts

Life loss ( Historical schools)

Large cost of renovation
after earthquake

Arg-e-Bam and Bam earthquake,2003
The largest adobe building in the world
The origins of Bam : 6th to 4th centuries BC

Before Bam Earthquake,2003

After Bam Earthquake,2003

Time needed for rebuild of this structure after damage of Bam earthquake :12 years
Total cost for rebuild : 120 million $

Before Bam Earthquake,2003

After Bam Earthquake,2003

Solution

Why Center core?
others
1%

concrete
2%
steel
8%

Large number of
masonry buildings
Masonry
89%

Non-destructive method

Without Evacuation

Steps

Problems

Perforating the
masonry walls

How to perforate masonry walls
without any cracks on wall
surface

Placing bars in
holes

Area, Distance, Number of bars

Placing grout
in holes

Properties of grout

the building was studied under the critical conditions
Very weak mortar

Strong bricks

Loose finishing of the wall
Wall thickness is at most
30 centimetres
selected school: Do Shahid
The building has 3 The
stories
Aged about 50 years

Parts of Drilling systems
Drilling Machine

Rod

Hydraulic

Rotary

Drilling
Rod transmits
machinethe
produces
rotatingthe
force
energy
to the stabilizer
for rotation
and
ofbit
the bit

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer
Stabilizer reduces the lateral movements
and bit shaking along the drilling path

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer

Bits

Bit penetrates through the depth and
determines the drilling path

Principle of design
4 boreholes (total 28 m height) were perforated in this project.
In each borehole, drilling technique, equipments and bits were
changed or design according to the damage in the wall surface .
After observation of these cracks the wall surface was
destructed; moreover, a new bit or stabilizer was designed
according to movement of bit on surface of bricks and other
observations ( air pressure, rotation of bit ...) to obtain the most
suitable ones.

Step 1: changing available Bits and Stabilizers
in drilling to obtain general vision for next step
Bit properties

Diamond
Non coring
D: 76 mm
Diamond
Coring
D: 76 mm

TC
Coring
D: 93mm

picture

Damage
Bit deviation due to large
contact surface with cement

How we deal with this
new
Cracks were observed In the
part of the wall due
problem? weakest
to high air pressure and lack
of mortar in the gap between
two bricks, the air flow pushes
the finishing and damages it
such that cuttings were
dispersed.

Bit properties

TC
Non coring
D: 93 mm

picture

Damage

Cracks appear due to weak
bricking

Good Suggestion for next step
TC
Non coring
D: 66mm

Finishing remains unhurt

Step 2: Designing new bits and stabilizers by
result of past drillings

TC
Non coring
D: 76 mm
TC 6 mm×6mm

New changes:
Increaseof TC dimension: 6 mm×6mm

New ways for exist of cuttings

Step 2: Designing new bits and stabilizers by
result of past drillings

Increase
dimension of
cuttings

A Cutting act
as a base

Spiral motion
of drilling
system

Crack in wall
surface

To prevent spiral motion and lateral motion Special
stabilization was designed

These holes were considered for escape of cuttings
Adding this type of stabilization decrease lateral movement; however, these holes
do not supply enough area for escape of cuttings

……Other bits and a stabilizer were designed and
cracks that appeared in each step led to
development of final drilling system and technical
drilling….

Final Bit

Final Bit

Final Bit

Final Bit

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

How the new designed bit act?

Masonry Wall

Rod

Escape line
Of cuttings
Masonry Wall

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

Conclusion
1. Rate of penetration with non-coring bits is high. However, these bits
are not as precise as coring bits. In spite of high precision coring bits
are not so fast due to several pull out of the bits for emptying the
cores.
2. If non-coring bits are used, as the size of TCs increases, the
deviation of the hole will increase. Larger cuttings lead to asymmetric
engagement of TC and cuttings and make a permanent change in the
axis of rotation.

Conclusion
3. Stabilizers are used to increase the accuracy and decrease the
deviation in drilling path. Although, it must be noted that they
increase air pressure on the surface of the holes and crack the
finishing.
4. The most important result of this study is the combination of coring
and non-coring bits. To stabilize the drilling path and decrease the
deviation, a guide is installed on the TC-Non-Coring bit instead of
stabilizers. On the whole, this drilling bit contains a TC Coring bit
which cores from the masonry walls. This bit penetrates through the
wall as a guide and prevents the bit from deviation and out of axis
rotation. In a short distance from the TC-Coring bit, TC Non-Coring bit
is installed. This bit crushes the cores and makes the cuttings ready for
being removed from the hole as dust. The smaller the cuttings are, the
lower air pressure is needed to remove them.

Conclusion
5. This newly invented bit could use for mining, oil and other
excavations as well.
6. Hydraulic drilling machines have a better performance
compared to SGZ Rotary machine because they are larger.
7. The drilling technique must be such that the bit pressure would
be minimum.

Conclusion
8. The brick type, mortar and the quality of bricking are
determining factors for setting the drilling speed and air pressure.
It seems that we can’t have exact quantities of such factors now;
however, an expert drilling operator may achieve this.

9. During drilling operation, the speed of rotation and air pressure
could be set by observing the size of cuttings. An expert can
minimize the size of cuttings by paying attention to it.

Thanks for your kind Attention


Slide 9

Perforating the masonry walls in
rehabilitation of masonry
Buildings using center core method
Alireza Mahdizadeh - Jamaledin Borzouie

Center core method is the good suggestion for retrofitting of
Historical masonry buildings due to non-destructive
construction.

Importance of Historical Buildings
Cultural Importance
Economy of tourists

Economic Impacts

Life loss ( Historical schools)

Large cost of renovation
after earthquake

Arg-e-Bam and Bam earthquake,2003
The largest adobe building in the world
The origins of Bam : 6th to 4th centuries BC

Before Bam Earthquake,2003

After Bam Earthquake,2003

Time needed for rebuild of this structure after damage of Bam earthquake :12 years
Total cost for rebuild : 120 million $

Before Bam Earthquake,2003

After Bam Earthquake,2003

Solution

Why Center core?
others
1%

concrete
2%
steel
8%

Large number of
masonry buildings
Masonry
89%

Non-destructive method

Without Evacuation

Steps

Problems

Perforating the
masonry walls

How to perforate masonry walls
without any cracks on wall
surface

Placing bars in
holes

Area, Distance, Number of bars

Placing grout
in holes

Properties of grout

the building was studied under the critical conditions
Very weak mortar

Strong bricks

Loose finishing of the wall
Wall thickness is at most
30 centimetres
selected school: Do Shahid
The building has 3 The
stories
Aged about 50 years

Parts of Drilling systems
Drilling Machine

Rod

Hydraulic

Rotary

Drilling
Rod transmits
machinethe
produces
rotatingthe
force
energy
to the stabilizer
for rotation
and
ofbit
the bit

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer
Stabilizer reduces the lateral movements
and bit shaking along the drilling path

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer

Bits

Bit penetrates through the depth and
determines the drilling path

Principle of design
4 boreholes (total 28 m height) were perforated in this project.
In each borehole, drilling technique, equipments and bits were
changed or design according to the damage in the wall surface .
After observation of these cracks the wall surface was
destructed; moreover, a new bit or stabilizer was designed
according to movement of bit on surface of bricks and other
observations ( air pressure, rotation of bit ...) to obtain the most
suitable ones.

Step 1: changing available Bits and Stabilizers
in drilling to obtain general vision for next step
Bit properties

Diamond
Non coring
D: 76 mm
Diamond
Coring
D: 76 mm

TC
Coring
D: 93mm

picture

Damage
Bit deviation due to large
contact surface with cement

How we deal with this
new
Cracks were observed In the
part of the wall due
problem? weakest
to high air pressure and lack
of mortar in the gap between
two bricks, the air flow pushes
the finishing and damages it
such that cuttings were
dispersed.

Bit properties

TC
Non coring
D: 93 mm

picture

Damage

Cracks appear due to weak
bricking

Good Suggestion for next step
TC
Non coring
D: 66mm

Finishing remains unhurt

Step 2: Designing new bits and stabilizers by
result of past drillings

TC
Non coring
D: 76 mm
TC 6 mm×6mm

New changes:
Increaseof TC dimension: 6 mm×6mm

New ways for exist of cuttings

Step 2: Designing new bits and stabilizers by
result of past drillings

Increase
dimension of
cuttings

A Cutting act
as a base

Spiral motion
of drilling
system

Crack in wall
surface

To prevent spiral motion and lateral motion Special
stabilization was designed

These holes were considered for escape of cuttings
Adding this type of stabilization decrease lateral movement; however, these holes
do not supply enough area for escape of cuttings

……Other bits and a stabilizer were designed and
cracks that appeared in each step led to
development of final drilling system and technical
drilling….

Final Bit

Final Bit

Final Bit

Final Bit

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

How the new designed bit act?

Masonry Wall

Rod

Escape line
Of cuttings
Masonry Wall

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

Conclusion
1. Rate of penetration with non-coring bits is high. However, these bits
are not as precise as coring bits. In spite of high precision coring bits
are not so fast due to several pull out of the bits for emptying the
cores.
2. If non-coring bits are used, as the size of TCs increases, the
deviation of the hole will increase. Larger cuttings lead to asymmetric
engagement of TC and cuttings and make a permanent change in the
axis of rotation.

Conclusion
3. Stabilizers are used to increase the accuracy and decrease the
deviation in drilling path. Although, it must be noted that they
increase air pressure on the surface of the holes and crack the
finishing.
4. The most important result of this study is the combination of coring
and non-coring bits. To stabilize the drilling path and decrease the
deviation, a guide is installed on the TC-Non-Coring bit instead of
stabilizers. On the whole, this drilling bit contains a TC Coring bit
which cores from the masonry walls. This bit penetrates through the
wall as a guide and prevents the bit from deviation and out of axis
rotation. In a short distance from the TC-Coring bit, TC Non-Coring bit
is installed. This bit crushes the cores and makes the cuttings ready for
being removed from the hole as dust. The smaller the cuttings are, the
lower air pressure is needed to remove them.

Conclusion
5. This newly invented bit could use for mining, oil and other
excavations as well.
6. Hydraulic drilling machines have a better performance
compared to SGZ Rotary machine because they are larger.
7. The drilling technique must be such that the bit pressure would
be minimum.

Conclusion
8. The brick type, mortar and the quality of bricking are
determining factors for setting the drilling speed and air pressure.
It seems that we can’t have exact quantities of such factors now;
however, an expert drilling operator may achieve this.

9. During drilling operation, the speed of rotation and air pressure
could be set by observing the size of cuttings. An expert can
minimize the size of cuttings by paying attention to it.

Thanks for your kind Attention


Slide 10

Perforating the masonry walls in
rehabilitation of masonry
Buildings using center core method
Alireza Mahdizadeh - Jamaledin Borzouie

Center core method is the good suggestion for retrofitting of
Historical masonry buildings due to non-destructive
construction.

Importance of Historical Buildings
Cultural Importance
Economy of tourists

Economic Impacts

Life loss ( Historical schools)

Large cost of renovation
after earthquake

Arg-e-Bam and Bam earthquake,2003
The largest adobe building in the world
The origins of Bam : 6th to 4th centuries BC

Before Bam Earthquake,2003

After Bam Earthquake,2003

Time needed for rebuild of this structure after damage of Bam earthquake :12 years
Total cost for rebuild : 120 million $

Before Bam Earthquake,2003

After Bam Earthquake,2003

Solution

Why Center core?
others
1%

concrete
2%
steel
8%

Large number of
masonry buildings
Masonry
89%

Non-destructive method

Without Evacuation

Steps

Problems

Perforating the
masonry walls

How to perforate masonry walls
without any cracks on wall
surface

Placing bars in
holes

Area, Distance, Number of bars

Placing grout
in holes

Properties of grout

the building was studied under the critical conditions
Very weak mortar

Strong bricks

Loose finishing of the wall
Wall thickness is at most
30 centimetres
selected school: Do Shahid
The building has 3 The
stories
Aged about 50 years

Parts of Drilling systems
Drilling Machine

Rod

Hydraulic

Rotary

Drilling
Rod transmits
machinethe
produces
rotatingthe
force
energy
to the stabilizer
for rotation
and
ofbit
the bit

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer
Stabilizer reduces the lateral movements
and bit shaking along the drilling path

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer

Bits

Bit penetrates through the depth and
determines the drilling path

Principle of design
4 boreholes (total 28 m height) were perforated in this project.
In each borehole, drilling technique, equipments and bits were
changed or design according to the damage in the wall surface .
After observation of these cracks the wall surface was
destructed; moreover, a new bit or stabilizer was designed
according to movement of bit on surface of bricks and other
observations ( air pressure, rotation of bit ...) to obtain the most
suitable ones.

Step 1: changing available Bits and Stabilizers
in drilling to obtain general vision for next step
Bit properties

Diamond
Non coring
D: 76 mm
Diamond
Coring
D: 76 mm

TC
Coring
D: 93mm

picture

Damage
Bit deviation due to large
contact surface with cement

How we deal with this
new
Cracks were observed In the
part of the wall due
problem? weakest
to high air pressure and lack
of mortar in the gap between
two bricks, the air flow pushes
the finishing and damages it
such that cuttings were
dispersed.

Bit properties

TC
Non coring
D: 93 mm

picture

Damage

Cracks appear due to weak
bricking

Good Suggestion for next step
TC
Non coring
D: 66mm

Finishing remains unhurt

Step 2: Designing new bits and stabilizers by
result of past drillings

TC
Non coring
D: 76 mm
TC 6 mm×6mm

New changes:
Increaseof TC dimension: 6 mm×6mm

New ways for exist of cuttings

Step 2: Designing new bits and stabilizers by
result of past drillings

Increase
dimension of
cuttings

A Cutting act
as a base

Spiral motion
of drilling
system

Crack in wall
surface

To prevent spiral motion and lateral motion Special
stabilization was designed

These holes were considered for escape of cuttings
Adding this type of stabilization decrease lateral movement; however, these holes
do not supply enough area for escape of cuttings

……Other bits and a stabilizer were designed and
cracks that appeared in each step led to
development of final drilling system and technical
drilling….

Final Bit

Final Bit

Final Bit

Final Bit

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

How the new designed bit act?

Masonry Wall

Rod

Escape line
Of cuttings
Masonry Wall

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

Conclusion
1. Rate of penetration with non-coring bits is high. However, these bits
are not as precise as coring bits. In spite of high precision coring bits
are not so fast due to several pull out of the bits for emptying the
cores.
2. If non-coring bits are used, as the size of TCs increases, the
deviation of the hole will increase. Larger cuttings lead to asymmetric
engagement of TC and cuttings and make a permanent change in the
axis of rotation.

Conclusion
3. Stabilizers are used to increase the accuracy and decrease the
deviation in drilling path. Although, it must be noted that they
increase air pressure on the surface of the holes and crack the
finishing.
4. The most important result of this study is the combination of coring
and non-coring bits. To stabilize the drilling path and decrease the
deviation, a guide is installed on the TC-Non-Coring bit instead of
stabilizers. On the whole, this drilling bit contains a TC Coring bit
which cores from the masonry walls. This bit penetrates through the
wall as a guide and prevents the bit from deviation and out of axis
rotation. In a short distance from the TC-Coring bit, TC Non-Coring bit
is installed. This bit crushes the cores and makes the cuttings ready for
being removed from the hole as dust. The smaller the cuttings are, the
lower air pressure is needed to remove them.

Conclusion
5. This newly invented bit could use for mining, oil and other
excavations as well.
6. Hydraulic drilling machines have a better performance
compared to SGZ Rotary machine because they are larger.
7. The drilling technique must be such that the bit pressure would
be minimum.

Conclusion
8. The brick type, mortar and the quality of bricking are
determining factors for setting the drilling speed and air pressure.
It seems that we can’t have exact quantities of such factors now;
however, an expert drilling operator may achieve this.

9. During drilling operation, the speed of rotation and air pressure
could be set by observing the size of cuttings. An expert can
minimize the size of cuttings by paying attention to it.

Thanks for your kind Attention


Slide 11

Perforating the masonry walls in
rehabilitation of masonry
Buildings using center core method
Alireza Mahdizadeh - Jamaledin Borzouie

Center core method is the good suggestion for retrofitting of
Historical masonry buildings due to non-destructive
construction.

Importance of Historical Buildings
Cultural Importance
Economy of tourists

Economic Impacts

Life loss ( Historical schools)

Large cost of renovation
after earthquake

Arg-e-Bam and Bam earthquake,2003
The largest adobe building in the world
The origins of Bam : 6th to 4th centuries BC

Before Bam Earthquake,2003

After Bam Earthquake,2003

Time needed for rebuild of this structure after damage of Bam earthquake :12 years
Total cost for rebuild : 120 million $

Before Bam Earthquake,2003

After Bam Earthquake,2003

Solution

Why Center core?
others
1%

concrete
2%
steel
8%

Large number of
masonry buildings
Masonry
89%

Non-destructive method

Without Evacuation

Steps

Problems

Perforating the
masonry walls

How to perforate masonry walls
without any cracks on wall
surface

Placing bars in
holes

Area, Distance, Number of bars

Placing grout
in holes

Properties of grout

the building was studied under the critical conditions
Very weak mortar

Strong bricks

Loose finishing of the wall
Wall thickness is at most
30 centimetres
selected school: Do Shahid
The building has 3 The
stories
Aged about 50 years

Parts of Drilling systems
Drilling Machine

Rod

Hydraulic

Rotary

Drilling
Rod transmits
machinethe
produces
rotatingthe
force
energy
to the stabilizer
for rotation
and
ofbit
the bit

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer
Stabilizer reduces the lateral movements
and bit shaking along the drilling path

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer

Bits

Bit penetrates through the depth and
determines the drilling path

Principle of design
4 boreholes (total 28 m height) were perforated in this project.
In each borehole, drilling technique, equipments and bits were
changed or design according to the damage in the wall surface .
After observation of these cracks the wall surface was
destructed; moreover, a new bit or stabilizer was designed
according to movement of bit on surface of bricks and other
observations ( air pressure, rotation of bit ...) to obtain the most
suitable ones.

Step 1: changing available Bits and Stabilizers
in drilling to obtain general vision for next step
Bit properties

Diamond
Non coring
D: 76 mm
Diamond
Coring
D: 76 mm

TC
Coring
D: 93mm

picture

Damage
Bit deviation due to large
contact surface with cement

How we deal with this
new
Cracks were observed In the
part of the wall due
problem? weakest
to high air pressure and lack
of mortar in the gap between
two bricks, the air flow pushes
the finishing and damages it
such that cuttings were
dispersed.

Bit properties

TC
Non coring
D: 93 mm

picture

Damage

Cracks appear due to weak
bricking

Good Suggestion for next step
TC
Non coring
D: 66mm

Finishing remains unhurt

Step 2: Designing new bits and stabilizers by
result of past drillings

TC
Non coring
D: 76 mm
TC 6 mm×6mm

New changes:
Increaseof TC dimension: 6 mm×6mm

New ways for exist of cuttings

Step 2: Designing new bits and stabilizers by
result of past drillings

Increase
dimension of
cuttings

A Cutting act
as a base

Spiral motion
of drilling
system

Crack in wall
surface

To prevent spiral motion and lateral motion Special
stabilization was designed

These holes were considered for escape of cuttings
Adding this type of stabilization decrease lateral movement; however, these holes
do not supply enough area for escape of cuttings

……Other bits and a stabilizer were designed and
cracks that appeared in each step led to
development of final drilling system and technical
drilling….

Final Bit

Final Bit

Final Bit

Final Bit

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

How the new designed bit act?

Masonry Wall

Rod

Escape line
Of cuttings
Masonry Wall

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

Conclusion
1. Rate of penetration with non-coring bits is high. However, these bits
are not as precise as coring bits. In spite of high precision coring bits
are not so fast due to several pull out of the bits for emptying the
cores.
2. If non-coring bits are used, as the size of TCs increases, the
deviation of the hole will increase. Larger cuttings lead to asymmetric
engagement of TC and cuttings and make a permanent change in the
axis of rotation.

Conclusion
3. Stabilizers are used to increase the accuracy and decrease the
deviation in drilling path. Although, it must be noted that they
increase air pressure on the surface of the holes and crack the
finishing.
4. The most important result of this study is the combination of coring
and non-coring bits. To stabilize the drilling path and decrease the
deviation, a guide is installed on the TC-Non-Coring bit instead of
stabilizers. On the whole, this drilling bit contains a TC Coring bit
which cores from the masonry walls. This bit penetrates through the
wall as a guide and prevents the bit from deviation and out of axis
rotation. In a short distance from the TC-Coring bit, TC Non-Coring bit
is installed. This bit crushes the cores and makes the cuttings ready for
being removed from the hole as dust. The smaller the cuttings are, the
lower air pressure is needed to remove them.

Conclusion
5. This newly invented bit could use for mining, oil and other
excavations as well.
6. Hydraulic drilling machines have a better performance
compared to SGZ Rotary machine because they are larger.
7. The drilling technique must be such that the bit pressure would
be minimum.

Conclusion
8. The brick type, mortar and the quality of bricking are
determining factors for setting the drilling speed and air pressure.
It seems that we can’t have exact quantities of such factors now;
however, an expert drilling operator may achieve this.

9. During drilling operation, the speed of rotation and air pressure
could be set by observing the size of cuttings. An expert can
minimize the size of cuttings by paying attention to it.

Thanks for your kind Attention


Slide 12

Perforating the masonry walls in
rehabilitation of masonry
Buildings using center core method
Alireza Mahdizadeh - Jamaledin Borzouie

Center core method is the good suggestion for retrofitting of
Historical masonry buildings due to non-destructive
construction.

Importance of Historical Buildings
Cultural Importance
Economy of tourists

Economic Impacts

Life loss ( Historical schools)

Large cost of renovation
after earthquake

Arg-e-Bam and Bam earthquake,2003
The largest adobe building in the world
The origins of Bam : 6th to 4th centuries BC

Before Bam Earthquake,2003

After Bam Earthquake,2003

Time needed for rebuild of this structure after damage of Bam earthquake :12 years
Total cost for rebuild : 120 million $

Before Bam Earthquake,2003

After Bam Earthquake,2003

Solution

Why Center core?
others
1%

concrete
2%
steel
8%

Large number of
masonry buildings
Masonry
89%

Non-destructive method

Without Evacuation

Steps

Problems

Perforating the
masonry walls

How to perforate masonry walls
without any cracks on wall
surface

Placing bars in
holes

Area, Distance, Number of bars

Placing grout
in holes

Properties of grout

the building was studied under the critical conditions
Very weak mortar

Strong bricks

Loose finishing of the wall
Wall thickness is at most
30 centimetres
selected school: Do Shahid
The building has 3 The
stories
Aged about 50 years

Parts of Drilling systems
Drilling Machine

Rod

Hydraulic

Rotary

Drilling
Rod transmits
machinethe
produces
rotatingthe
force
energy
to the stabilizer
for rotation
and
ofbit
the bit

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer
Stabilizer reduces the lateral movements
and bit shaking along the drilling path

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer

Bits

Bit penetrates through the depth and
determines the drilling path

Principle of design
4 boreholes (total 28 m height) were perforated in this project.
In each borehole, drilling technique, equipments and bits were
changed or design according to the damage in the wall surface .
After observation of these cracks the wall surface was
destructed; moreover, a new bit or stabilizer was designed
according to movement of bit on surface of bricks and other
observations ( air pressure, rotation of bit ...) to obtain the most
suitable ones.

Step 1: changing available Bits and Stabilizers
in drilling to obtain general vision for next step
Bit properties

Diamond
Non coring
D: 76 mm
Diamond
Coring
D: 76 mm

TC
Coring
D: 93mm

picture

Damage
Bit deviation due to large
contact surface with cement

How we deal with this
new
Cracks were observed In the
part of the wall due
problem? weakest
to high air pressure and lack
of mortar in the gap between
two bricks, the air flow pushes
the finishing and damages it
such that cuttings were
dispersed.

Bit properties

TC
Non coring
D: 93 mm

picture

Damage

Cracks appear due to weak
bricking

Good Suggestion for next step
TC
Non coring
D: 66mm

Finishing remains unhurt

Step 2: Designing new bits and stabilizers by
result of past drillings

TC
Non coring
D: 76 mm
TC 6 mm×6mm

New changes:
Increaseof TC dimension: 6 mm×6mm

New ways for exist of cuttings

Step 2: Designing new bits and stabilizers by
result of past drillings

Increase
dimension of
cuttings

A Cutting act
as a base

Spiral motion
of drilling
system

Crack in wall
surface

To prevent spiral motion and lateral motion Special
stabilization was designed

These holes were considered for escape of cuttings
Adding this type of stabilization decrease lateral movement; however, these holes
do not supply enough area for escape of cuttings

……Other bits and a stabilizer were designed and
cracks that appeared in each step led to
development of final drilling system and technical
drilling….

Final Bit

Final Bit

Final Bit

Final Bit

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

How the new designed bit act?

Masonry Wall

Rod

Escape line
Of cuttings
Masonry Wall

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

Conclusion
1. Rate of penetration with non-coring bits is high. However, these bits
are not as precise as coring bits. In spite of high precision coring bits
are not so fast due to several pull out of the bits for emptying the
cores.
2. If non-coring bits are used, as the size of TCs increases, the
deviation of the hole will increase. Larger cuttings lead to asymmetric
engagement of TC and cuttings and make a permanent change in the
axis of rotation.

Conclusion
3. Stabilizers are used to increase the accuracy and decrease the
deviation in drilling path. Although, it must be noted that they
increase air pressure on the surface of the holes and crack the
finishing.
4. The most important result of this study is the combination of coring
and non-coring bits. To stabilize the drilling path and decrease the
deviation, a guide is installed on the TC-Non-Coring bit instead of
stabilizers. On the whole, this drilling bit contains a TC Coring bit
which cores from the masonry walls. This bit penetrates through the
wall as a guide and prevents the bit from deviation and out of axis
rotation. In a short distance from the TC-Coring bit, TC Non-Coring bit
is installed. This bit crushes the cores and makes the cuttings ready for
being removed from the hole as dust. The smaller the cuttings are, the
lower air pressure is needed to remove them.

Conclusion
5. This newly invented bit could use for mining, oil and other
excavations as well.
6. Hydraulic drilling machines have a better performance
compared to SGZ Rotary machine because they are larger.
7. The drilling technique must be such that the bit pressure would
be minimum.

Conclusion
8. The brick type, mortar and the quality of bricking are
determining factors for setting the drilling speed and air pressure.
It seems that we can’t have exact quantities of such factors now;
however, an expert drilling operator may achieve this.

9. During drilling operation, the speed of rotation and air pressure
could be set by observing the size of cuttings. An expert can
minimize the size of cuttings by paying attention to it.

Thanks for your kind Attention


Slide 13

Perforating the masonry walls in
rehabilitation of masonry
Buildings using center core method
Alireza Mahdizadeh - Jamaledin Borzouie

Center core method is the good suggestion for retrofitting of
Historical masonry buildings due to non-destructive
construction.

Importance of Historical Buildings
Cultural Importance
Economy of tourists

Economic Impacts

Life loss ( Historical schools)

Large cost of renovation
after earthquake

Arg-e-Bam and Bam earthquake,2003
The largest adobe building in the world
The origins of Bam : 6th to 4th centuries BC

Before Bam Earthquake,2003

After Bam Earthquake,2003

Time needed for rebuild of this structure after damage of Bam earthquake :12 years
Total cost for rebuild : 120 million $

Before Bam Earthquake,2003

After Bam Earthquake,2003

Solution

Why Center core?
others
1%

concrete
2%
steel
8%

Large number of
masonry buildings
Masonry
89%

Non-destructive method

Without Evacuation

Steps

Problems

Perforating the
masonry walls

How to perforate masonry walls
without any cracks on wall
surface

Placing bars in
holes

Area, Distance, Number of bars

Placing grout
in holes

Properties of grout

the building was studied under the critical conditions
Very weak mortar

Strong bricks

Loose finishing of the wall
Wall thickness is at most
30 centimetres
selected school: Do Shahid
The building has 3 The
stories
Aged about 50 years

Parts of Drilling systems
Drilling Machine

Rod

Hydraulic

Rotary

Drilling
Rod transmits
machinethe
produces
rotatingthe
force
energy
to the stabilizer
for rotation
and
ofbit
the bit

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer
Stabilizer reduces the lateral movements
and bit shaking along the drilling path

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer

Bits

Bit penetrates through the depth and
determines the drilling path

Principle of design
4 boreholes (total 28 m height) were perforated in this project.
In each borehole, drilling technique, equipments and bits were
changed or design according to the damage in the wall surface .
After observation of these cracks the wall surface was
destructed; moreover, a new bit or stabilizer was designed
according to movement of bit on surface of bricks and other
observations ( air pressure, rotation of bit ...) to obtain the most
suitable ones.

Step 1: changing available Bits and Stabilizers
in drilling to obtain general vision for next step
Bit properties

Diamond
Non coring
D: 76 mm
Diamond
Coring
D: 76 mm

TC
Coring
D: 93mm

picture

Damage
Bit deviation due to large
contact surface with cement

How we deal with this
new
Cracks were observed In the
part of the wall due
problem? weakest
to high air pressure and lack
of mortar in the gap between
two bricks, the air flow pushes
the finishing and damages it
such that cuttings were
dispersed.

Bit properties

TC
Non coring
D: 93 mm

picture

Damage

Cracks appear due to weak
bricking

Good Suggestion for next step
TC
Non coring
D: 66mm

Finishing remains unhurt

Step 2: Designing new bits and stabilizers by
result of past drillings

TC
Non coring
D: 76 mm
TC 6 mm×6mm

New changes:
Increaseof TC dimension: 6 mm×6mm

New ways for exist of cuttings

Step 2: Designing new bits and stabilizers by
result of past drillings

Increase
dimension of
cuttings

A Cutting act
as a base

Spiral motion
of drilling
system

Crack in wall
surface

To prevent spiral motion and lateral motion Special
stabilization was designed

These holes were considered for escape of cuttings
Adding this type of stabilization decrease lateral movement; however, these holes
do not supply enough area for escape of cuttings

……Other bits and a stabilizer were designed and
cracks that appeared in each step led to
development of final drilling system and technical
drilling….

Final Bit

Final Bit

Final Bit

Final Bit

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

How the new designed bit act?

Masonry Wall

Rod

Escape line
Of cuttings
Masonry Wall

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

Conclusion
1. Rate of penetration with non-coring bits is high. However, these bits
are not as precise as coring bits. In spite of high precision coring bits
are not so fast due to several pull out of the bits for emptying the
cores.
2. If non-coring bits are used, as the size of TCs increases, the
deviation of the hole will increase. Larger cuttings lead to asymmetric
engagement of TC and cuttings and make a permanent change in the
axis of rotation.

Conclusion
3. Stabilizers are used to increase the accuracy and decrease the
deviation in drilling path. Although, it must be noted that they
increase air pressure on the surface of the holes and crack the
finishing.
4. The most important result of this study is the combination of coring
and non-coring bits. To stabilize the drilling path and decrease the
deviation, a guide is installed on the TC-Non-Coring bit instead of
stabilizers. On the whole, this drilling bit contains a TC Coring bit
which cores from the masonry walls. This bit penetrates through the
wall as a guide and prevents the bit from deviation and out of axis
rotation. In a short distance from the TC-Coring bit, TC Non-Coring bit
is installed. This bit crushes the cores and makes the cuttings ready for
being removed from the hole as dust. The smaller the cuttings are, the
lower air pressure is needed to remove them.

Conclusion
5. This newly invented bit could use for mining, oil and other
excavations as well.
6. Hydraulic drilling machines have a better performance
compared to SGZ Rotary machine because they are larger.
7. The drilling technique must be such that the bit pressure would
be minimum.

Conclusion
8. The brick type, mortar and the quality of bricking are
determining factors for setting the drilling speed and air pressure.
It seems that we can’t have exact quantities of such factors now;
however, an expert drilling operator may achieve this.

9. During drilling operation, the speed of rotation and air pressure
could be set by observing the size of cuttings. An expert can
minimize the size of cuttings by paying attention to it.

Thanks for your kind Attention


Slide 14

Perforating the masonry walls in
rehabilitation of masonry
Buildings using center core method
Alireza Mahdizadeh - Jamaledin Borzouie

Center core method is the good suggestion for retrofitting of
Historical masonry buildings due to non-destructive
construction.

Importance of Historical Buildings
Cultural Importance
Economy of tourists

Economic Impacts

Life loss ( Historical schools)

Large cost of renovation
after earthquake

Arg-e-Bam and Bam earthquake,2003
The largest adobe building in the world
The origins of Bam : 6th to 4th centuries BC

Before Bam Earthquake,2003

After Bam Earthquake,2003

Time needed for rebuild of this structure after damage of Bam earthquake :12 years
Total cost for rebuild : 120 million $

Before Bam Earthquake,2003

After Bam Earthquake,2003

Solution

Why Center core?
others
1%

concrete
2%
steel
8%

Large number of
masonry buildings
Masonry
89%

Non-destructive method

Without Evacuation

Steps

Problems

Perforating the
masonry walls

How to perforate masonry walls
without any cracks on wall
surface

Placing bars in
holes

Area, Distance, Number of bars

Placing grout
in holes

Properties of grout

the building was studied under the critical conditions
Very weak mortar

Strong bricks

Loose finishing of the wall
Wall thickness is at most
30 centimetres
selected school: Do Shahid
The building has 3 The
stories
Aged about 50 years

Parts of Drilling systems
Drilling Machine

Rod

Hydraulic

Rotary

Drilling
Rod transmits
machinethe
produces
rotatingthe
force
energy
to the stabilizer
for rotation
and
ofbit
the bit

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer
Stabilizer reduces the lateral movements
and bit shaking along the drilling path

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer

Bits

Bit penetrates through the depth and
determines the drilling path

Principle of design
4 boreholes (total 28 m height) were perforated in this project.
In each borehole, drilling technique, equipments and bits were
changed or design according to the damage in the wall surface .
After observation of these cracks the wall surface was
destructed; moreover, a new bit or stabilizer was designed
according to movement of bit on surface of bricks and other
observations ( air pressure, rotation of bit ...) to obtain the most
suitable ones.

Step 1: changing available Bits and Stabilizers
in drilling to obtain general vision for next step
Bit properties

Diamond
Non coring
D: 76 mm
Diamond
Coring
D: 76 mm

TC
Coring
D: 93mm

picture

Damage
Bit deviation due to large
contact surface with cement

How we deal with this
new
Cracks were observed In the
part of the wall due
problem? weakest
to high air pressure and lack
of mortar in the gap between
two bricks, the air flow pushes
the finishing and damages it
such that cuttings were
dispersed.

Bit properties

TC
Non coring
D: 93 mm

picture

Damage

Cracks appear due to weak
bricking

Good Suggestion for next step
TC
Non coring
D: 66mm

Finishing remains unhurt

Step 2: Designing new bits and stabilizers by
result of past drillings

TC
Non coring
D: 76 mm
TC 6 mm×6mm

New changes:
Increaseof TC dimension: 6 mm×6mm

New ways for exist of cuttings

Step 2: Designing new bits and stabilizers by
result of past drillings

Increase
dimension of
cuttings

A Cutting act
as a base

Spiral motion
of drilling
system

Crack in wall
surface

To prevent spiral motion and lateral motion Special
stabilization was designed

These holes were considered for escape of cuttings
Adding this type of stabilization decrease lateral movement; however, these holes
do not supply enough area for escape of cuttings

……Other bits and a stabilizer were designed and
cracks that appeared in each step led to
development of final drilling system and technical
drilling….

Final Bit

Final Bit

Final Bit

Final Bit

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

How the new designed bit act?

Masonry Wall

Rod

Escape line
Of cuttings
Masonry Wall

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

Conclusion
1. Rate of penetration with non-coring bits is high. However, these bits
are not as precise as coring bits. In spite of high precision coring bits
are not so fast due to several pull out of the bits for emptying the
cores.
2. If non-coring bits are used, as the size of TCs increases, the
deviation of the hole will increase. Larger cuttings lead to asymmetric
engagement of TC and cuttings and make a permanent change in the
axis of rotation.

Conclusion
3. Stabilizers are used to increase the accuracy and decrease the
deviation in drilling path. Although, it must be noted that they
increase air pressure on the surface of the holes and crack the
finishing.
4. The most important result of this study is the combination of coring
and non-coring bits. To stabilize the drilling path and decrease the
deviation, a guide is installed on the TC-Non-Coring bit instead of
stabilizers. On the whole, this drilling bit contains a TC Coring bit
which cores from the masonry walls. This bit penetrates through the
wall as a guide and prevents the bit from deviation and out of axis
rotation. In a short distance from the TC-Coring bit, TC Non-Coring bit
is installed. This bit crushes the cores and makes the cuttings ready for
being removed from the hole as dust. The smaller the cuttings are, the
lower air pressure is needed to remove them.

Conclusion
5. This newly invented bit could use for mining, oil and other
excavations as well.
6. Hydraulic drilling machines have a better performance
compared to SGZ Rotary machine because they are larger.
7. The drilling technique must be such that the bit pressure would
be minimum.

Conclusion
8. The brick type, mortar and the quality of bricking are
determining factors for setting the drilling speed and air pressure.
It seems that we can’t have exact quantities of such factors now;
however, an expert drilling operator may achieve this.

9. During drilling operation, the speed of rotation and air pressure
could be set by observing the size of cuttings. An expert can
minimize the size of cuttings by paying attention to it.

Thanks for your kind Attention


Slide 15

Perforating the masonry walls in
rehabilitation of masonry
Buildings using center core method
Alireza Mahdizadeh - Jamaledin Borzouie

Center core method is the good suggestion for retrofitting of
Historical masonry buildings due to non-destructive
construction.

Importance of Historical Buildings
Cultural Importance
Economy of tourists

Economic Impacts

Life loss ( Historical schools)

Large cost of renovation
after earthquake

Arg-e-Bam and Bam earthquake,2003
The largest adobe building in the world
The origins of Bam : 6th to 4th centuries BC

Before Bam Earthquake,2003

After Bam Earthquake,2003

Time needed for rebuild of this structure after damage of Bam earthquake :12 years
Total cost for rebuild : 120 million $

Before Bam Earthquake,2003

After Bam Earthquake,2003

Solution

Why Center core?
others
1%

concrete
2%
steel
8%

Large number of
masonry buildings
Masonry
89%

Non-destructive method

Without Evacuation

Steps

Problems

Perforating the
masonry walls

How to perforate masonry walls
without any cracks on wall
surface

Placing bars in
holes

Area, Distance, Number of bars

Placing grout
in holes

Properties of grout

the building was studied under the critical conditions
Very weak mortar

Strong bricks

Loose finishing of the wall
Wall thickness is at most
30 centimetres
selected school: Do Shahid
The building has 3 The
stories
Aged about 50 years

Parts of Drilling systems
Drilling Machine

Rod

Hydraulic

Rotary

Drilling
Rod transmits
machinethe
produces
rotatingthe
force
energy
to the stabilizer
for rotation
and
ofbit
the bit

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer
Stabilizer reduces the lateral movements
and bit shaking along the drilling path

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer

Bits

Bit penetrates through the depth and
determines the drilling path

Principle of design
4 boreholes (total 28 m height) were perforated in this project.
In each borehole, drilling technique, equipments and bits were
changed or design according to the damage in the wall surface .
After observation of these cracks the wall surface was
destructed; moreover, a new bit or stabilizer was designed
according to movement of bit on surface of bricks and other
observations ( air pressure, rotation of bit ...) to obtain the most
suitable ones.

Step 1: changing available Bits and Stabilizers
in drilling to obtain general vision for next step
Bit properties

Diamond
Non coring
D: 76 mm
Diamond
Coring
D: 76 mm

TC
Coring
D: 93mm

picture

Damage
Bit deviation due to large
contact surface with cement

How we deal with this
new
Cracks were observed In the
part of the wall due
problem? weakest
to high air pressure and lack
of mortar in the gap between
two bricks, the air flow pushes
the finishing and damages it
such that cuttings were
dispersed.

Bit properties

TC
Non coring
D: 93 mm

picture

Damage

Cracks appear due to weak
bricking

Good Suggestion for next step
TC
Non coring
D: 66mm

Finishing remains unhurt

Step 2: Designing new bits and stabilizers by
result of past drillings

TC
Non coring
D: 76 mm
TC 6 mm×6mm

New changes:
Increaseof TC dimension: 6 mm×6mm

New ways for exist of cuttings

Step 2: Designing new bits and stabilizers by
result of past drillings

Increase
dimension of
cuttings

A Cutting act
as a base

Spiral motion
of drilling
system

Crack in wall
surface

To prevent spiral motion and lateral motion Special
stabilization was designed

These holes were considered for escape of cuttings
Adding this type of stabilization decrease lateral movement; however, these holes
do not supply enough area for escape of cuttings

……Other bits and a stabilizer were designed and
cracks that appeared in each step led to
development of final drilling system and technical
drilling….

Final Bit

Final Bit

Final Bit

Final Bit

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

How the new designed bit act?

Masonry Wall

Rod

Escape line
Of cuttings
Masonry Wall

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

Conclusion
1. Rate of penetration with non-coring bits is high. However, these bits
are not as precise as coring bits. In spite of high precision coring bits
are not so fast due to several pull out of the bits for emptying the
cores.
2. If non-coring bits are used, as the size of TCs increases, the
deviation of the hole will increase. Larger cuttings lead to asymmetric
engagement of TC and cuttings and make a permanent change in the
axis of rotation.

Conclusion
3. Stabilizers are used to increase the accuracy and decrease the
deviation in drilling path. Although, it must be noted that they
increase air pressure on the surface of the holes and crack the
finishing.
4. The most important result of this study is the combination of coring
and non-coring bits. To stabilize the drilling path and decrease the
deviation, a guide is installed on the TC-Non-Coring bit instead of
stabilizers. On the whole, this drilling bit contains a TC Coring bit
which cores from the masonry walls. This bit penetrates through the
wall as a guide and prevents the bit from deviation and out of axis
rotation. In a short distance from the TC-Coring bit, TC Non-Coring bit
is installed. This bit crushes the cores and makes the cuttings ready for
being removed from the hole as dust. The smaller the cuttings are, the
lower air pressure is needed to remove them.

Conclusion
5. This newly invented bit could use for mining, oil and other
excavations as well.
6. Hydraulic drilling machines have a better performance
compared to SGZ Rotary machine because they are larger.
7. The drilling technique must be such that the bit pressure would
be minimum.

Conclusion
8. The brick type, mortar and the quality of bricking are
determining factors for setting the drilling speed and air pressure.
It seems that we can’t have exact quantities of such factors now;
however, an expert drilling operator may achieve this.

9. During drilling operation, the speed of rotation and air pressure
could be set by observing the size of cuttings. An expert can
minimize the size of cuttings by paying attention to it.

Thanks for your kind Attention


Slide 16

Perforating the masonry walls in
rehabilitation of masonry
Buildings using center core method
Alireza Mahdizadeh - Jamaledin Borzouie

Center core method is the good suggestion for retrofitting of
Historical masonry buildings due to non-destructive
construction.

Importance of Historical Buildings
Cultural Importance
Economy of tourists

Economic Impacts

Life loss ( Historical schools)

Large cost of renovation
after earthquake

Arg-e-Bam and Bam earthquake,2003
The largest adobe building in the world
The origins of Bam : 6th to 4th centuries BC

Before Bam Earthquake,2003

After Bam Earthquake,2003

Time needed for rebuild of this structure after damage of Bam earthquake :12 years
Total cost for rebuild : 120 million $

Before Bam Earthquake,2003

After Bam Earthquake,2003

Solution

Why Center core?
others
1%

concrete
2%
steel
8%

Large number of
masonry buildings
Masonry
89%

Non-destructive method

Without Evacuation

Steps

Problems

Perforating the
masonry walls

How to perforate masonry walls
without any cracks on wall
surface

Placing bars in
holes

Area, Distance, Number of bars

Placing grout
in holes

Properties of grout

the building was studied under the critical conditions
Very weak mortar

Strong bricks

Loose finishing of the wall
Wall thickness is at most
30 centimetres
selected school: Do Shahid
The building has 3 The
stories
Aged about 50 years

Parts of Drilling systems
Drilling Machine

Rod

Hydraulic

Rotary

Drilling
Rod transmits
machinethe
produces
rotatingthe
force
energy
to the stabilizer
for rotation
and
ofbit
the bit

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer
Stabilizer reduces the lateral movements
and bit shaking along the drilling path

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer

Bits

Bit penetrates through the depth and
determines the drilling path

Principle of design
4 boreholes (total 28 m height) were perforated in this project.
In each borehole, drilling technique, equipments and bits were
changed or design according to the damage in the wall surface .
After observation of these cracks the wall surface was
destructed; moreover, a new bit or stabilizer was designed
according to movement of bit on surface of bricks and other
observations ( air pressure, rotation of bit ...) to obtain the most
suitable ones.

Step 1: changing available Bits and Stabilizers
in drilling to obtain general vision for next step
Bit properties

Diamond
Non coring
D: 76 mm
Diamond
Coring
D: 76 mm

TC
Coring
D: 93mm

picture

Damage
Bit deviation due to large
contact surface with cement

How we deal with this
new
Cracks were observed In the
part of the wall due
problem? weakest
to high air pressure and lack
of mortar in the gap between
two bricks, the air flow pushes
the finishing and damages it
such that cuttings were
dispersed.

Bit properties

TC
Non coring
D: 93 mm

picture

Damage

Cracks appear due to weak
bricking

Good Suggestion for next step
TC
Non coring
D: 66mm

Finishing remains unhurt

Step 2: Designing new bits and stabilizers by
result of past drillings

TC
Non coring
D: 76 mm
TC 6 mm×6mm

New changes:
Increaseof TC dimension: 6 mm×6mm

New ways for exist of cuttings

Step 2: Designing new bits and stabilizers by
result of past drillings

Increase
dimension of
cuttings

A Cutting act
as a base

Spiral motion
of drilling
system

Crack in wall
surface

To prevent spiral motion and lateral motion Special
stabilization was designed

These holes were considered for escape of cuttings
Adding this type of stabilization decrease lateral movement; however, these holes
do not supply enough area for escape of cuttings

……Other bits and a stabilizer were designed and
cracks that appeared in each step led to
development of final drilling system and technical
drilling….

Final Bit

Final Bit

Final Bit

Final Bit

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

How the new designed bit act?

Masonry Wall

Rod

Escape line
Of cuttings
Masonry Wall

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

Conclusion
1. Rate of penetration with non-coring bits is high. However, these bits
are not as precise as coring bits. In spite of high precision coring bits
are not so fast due to several pull out of the bits for emptying the
cores.
2. If non-coring bits are used, as the size of TCs increases, the
deviation of the hole will increase. Larger cuttings lead to asymmetric
engagement of TC and cuttings and make a permanent change in the
axis of rotation.

Conclusion
3. Stabilizers are used to increase the accuracy and decrease the
deviation in drilling path. Although, it must be noted that they
increase air pressure on the surface of the holes and crack the
finishing.
4. The most important result of this study is the combination of coring
and non-coring bits. To stabilize the drilling path and decrease the
deviation, a guide is installed on the TC-Non-Coring bit instead of
stabilizers. On the whole, this drilling bit contains a TC Coring bit
which cores from the masonry walls. This bit penetrates through the
wall as a guide and prevents the bit from deviation and out of axis
rotation. In a short distance from the TC-Coring bit, TC Non-Coring bit
is installed. This bit crushes the cores and makes the cuttings ready for
being removed from the hole as dust. The smaller the cuttings are, the
lower air pressure is needed to remove them.

Conclusion
5. This newly invented bit could use for mining, oil and other
excavations as well.
6. Hydraulic drilling machines have a better performance
compared to SGZ Rotary machine because they are larger.
7. The drilling technique must be such that the bit pressure would
be minimum.

Conclusion
8. The brick type, mortar and the quality of bricking are
determining factors for setting the drilling speed and air pressure.
It seems that we can’t have exact quantities of such factors now;
however, an expert drilling operator may achieve this.

9. During drilling operation, the speed of rotation and air pressure
could be set by observing the size of cuttings. An expert can
minimize the size of cuttings by paying attention to it.

Thanks for your kind Attention


Slide 17

Perforating the masonry walls in
rehabilitation of masonry
Buildings using center core method
Alireza Mahdizadeh - Jamaledin Borzouie

Center core method is the good suggestion for retrofitting of
Historical masonry buildings due to non-destructive
construction.

Importance of Historical Buildings
Cultural Importance
Economy of tourists

Economic Impacts

Life loss ( Historical schools)

Large cost of renovation
after earthquake

Arg-e-Bam and Bam earthquake,2003
The largest adobe building in the world
The origins of Bam : 6th to 4th centuries BC

Before Bam Earthquake,2003

After Bam Earthquake,2003

Time needed for rebuild of this structure after damage of Bam earthquake :12 years
Total cost for rebuild : 120 million $

Before Bam Earthquake,2003

After Bam Earthquake,2003

Solution

Why Center core?
others
1%

concrete
2%
steel
8%

Large number of
masonry buildings
Masonry
89%

Non-destructive method

Without Evacuation

Steps

Problems

Perforating the
masonry walls

How to perforate masonry walls
without any cracks on wall
surface

Placing bars in
holes

Area, Distance, Number of bars

Placing grout
in holes

Properties of grout

the building was studied under the critical conditions
Very weak mortar

Strong bricks

Loose finishing of the wall
Wall thickness is at most
30 centimetres
selected school: Do Shahid
The building has 3 The
stories
Aged about 50 years

Parts of Drilling systems
Drilling Machine

Rod

Hydraulic

Rotary

Drilling
Rod transmits
machinethe
produces
rotatingthe
force
energy
to the stabilizer
for rotation
and
ofbit
the bit

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer
Stabilizer reduces the lateral movements
and bit shaking along the drilling path

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer

Bits

Bit penetrates through the depth and
determines the drilling path

Principle of design
4 boreholes (total 28 m height) were perforated in this project.
In each borehole, drilling technique, equipments and bits were
changed or design according to the damage in the wall surface .
After observation of these cracks the wall surface was
destructed; moreover, a new bit or stabilizer was designed
according to movement of bit on surface of bricks and other
observations ( air pressure, rotation of bit ...) to obtain the most
suitable ones.

Step 1: changing available Bits and Stabilizers
in drilling to obtain general vision for next step
Bit properties

Diamond
Non coring
D: 76 mm
Diamond
Coring
D: 76 mm

TC
Coring
D: 93mm

picture

Damage
Bit deviation due to large
contact surface with cement

How we deal with this
new
Cracks were observed In the
part of the wall due
problem? weakest
to high air pressure and lack
of mortar in the gap between
two bricks, the air flow pushes
the finishing and damages it
such that cuttings were
dispersed.

Bit properties

TC
Non coring
D: 93 mm

picture

Damage

Cracks appear due to weak
bricking

Good Suggestion for next step
TC
Non coring
D: 66mm

Finishing remains unhurt

Step 2: Designing new bits and stabilizers by
result of past drillings

TC
Non coring
D: 76 mm
TC 6 mm×6mm

New changes:
Increaseof TC dimension: 6 mm×6mm

New ways for exist of cuttings

Step 2: Designing new bits and stabilizers by
result of past drillings

Increase
dimension of
cuttings

A Cutting act
as a base

Spiral motion
of drilling
system

Crack in wall
surface

To prevent spiral motion and lateral motion Special
stabilization was designed

These holes were considered for escape of cuttings
Adding this type of stabilization decrease lateral movement; however, these holes
do not supply enough area for escape of cuttings

……Other bits and a stabilizer were designed and
cracks that appeared in each step led to
development of final drilling system and technical
drilling….

Final Bit

Final Bit

Final Bit

Final Bit

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

How the new designed bit act?

Masonry Wall

Rod

Escape line
Of cuttings
Masonry Wall

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

Conclusion
1. Rate of penetration with non-coring bits is high. However, these bits
are not as precise as coring bits. In spite of high precision coring bits
are not so fast due to several pull out of the bits for emptying the
cores.
2. If non-coring bits are used, as the size of TCs increases, the
deviation of the hole will increase. Larger cuttings lead to asymmetric
engagement of TC and cuttings and make a permanent change in the
axis of rotation.

Conclusion
3. Stabilizers are used to increase the accuracy and decrease the
deviation in drilling path. Although, it must be noted that they
increase air pressure on the surface of the holes and crack the
finishing.
4. The most important result of this study is the combination of coring
and non-coring bits. To stabilize the drilling path and decrease the
deviation, a guide is installed on the TC-Non-Coring bit instead of
stabilizers. On the whole, this drilling bit contains a TC Coring bit
which cores from the masonry walls. This bit penetrates through the
wall as a guide and prevents the bit from deviation and out of axis
rotation. In a short distance from the TC-Coring bit, TC Non-Coring bit
is installed. This bit crushes the cores and makes the cuttings ready for
being removed from the hole as dust. The smaller the cuttings are, the
lower air pressure is needed to remove them.

Conclusion
5. This newly invented bit could use for mining, oil and other
excavations as well.
6. Hydraulic drilling machines have a better performance
compared to SGZ Rotary machine because they are larger.
7. The drilling technique must be such that the bit pressure would
be minimum.

Conclusion
8. The brick type, mortar and the quality of bricking are
determining factors for setting the drilling speed and air pressure.
It seems that we can’t have exact quantities of such factors now;
however, an expert drilling operator may achieve this.

9. During drilling operation, the speed of rotation and air pressure
could be set by observing the size of cuttings. An expert can
minimize the size of cuttings by paying attention to it.

Thanks for your kind Attention


Slide 18

Perforating the masonry walls in
rehabilitation of masonry
Buildings using center core method
Alireza Mahdizadeh - Jamaledin Borzouie

Center core method is the good suggestion for retrofitting of
Historical masonry buildings due to non-destructive
construction.

Importance of Historical Buildings
Cultural Importance
Economy of tourists

Economic Impacts

Life loss ( Historical schools)

Large cost of renovation
after earthquake

Arg-e-Bam and Bam earthquake,2003
The largest adobe building in the world
The origins of Bam : 6th to 4th centuries BC

Before Bam Earthquake,2003

After Bam Earthquake,2003

Time needed for rebuild of this structure after damage of Bam earthquake :12 years
Total cost for rebuild : 120 million $

Before Bam Earthquake,2003

After Bam Earthquake,2003

Solution

Why Center core?
others
1%

concrete
2%
steel
8%

Large number of
masonry buildings
Masonry
89%

Non-destructive method

Without Evacuation

Steps

Problems

Perforating the
masonry walls

How to perforate masonry walls
without any cracks on wall
surface

Placing bars in
holes

Area, Distance, Number of bars

Placing grout
in holes

Properties of grout

the building was studied under the critical conditions
Very weak mortar

Strong bricks

Loose finishing of the wall
Wall thickness is at most
30 centimetres
selected school: Do Shahid
The building has 3 The
stories
Aged about 50 years

Parts of Drilling systems
Drilling Machine

Rod

Hydraulic

Rotary

Drilling
Rod transmits
machinethe
produces
rotatingthe
force
energy
to the stabilizer
for rotation
and
ofbit
the bit

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer
Stabilizer reduces the lateral movements
and bit shaking along the drilling path

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer

Bits

Bit penetrates through the depth and
determines the drilling path

Principle of design
4 boreholes (total 28 m height) were perforated in this project.
In each borehole, drilling technique, equipments and bits were
changed or design according to the damage in the wall surface .
After observation of these cracks the wall surface was
destructed; moreover, a new bit or stabilizer was designed
according to movement of bit on surface of bricks and other
observations ( air pressure, rotation of bit ...) to obtain the most
suitable ones.

Step 1: changing available Bits and Stabilizers
in drilling to obtain general vision for next step
Bit properties

Diamond
Non coring
D: 76 mm
Diamond
Coring
D: 76 mm

TC
Coring
D: 93mm

picture

Damage
Bit deviation due to large
contact surface with cement

How we deal with this
new
Cracks were observed In the
part of the wall due
problem? weakest
to high air pressure and lack
of mortar in the gap between
two bricks, the air flow pushes
the finishing and damages it
such that cuttings were
dispersed.

Bit properties

TC
Non coring
D: 93 mm

picture

Damage

Cracks appear due to weak
bricking

Good Suggestion for next step
TC
Non coring
D: 66mm

Finishing remains unhurt

Step 2: Designing new bits and stabilizers by
result of past drillings

TC
Non coring
D: 76 mm
TC 6 mm×6mm

New changes:
Increaseof TC dimension: 6 mm×6mm

New ways for exist of cuttings

Step 2: Designing new bits and stabilizers by
result of past drillings

Increase
dimension of
cuttings

A Cutting act
as a base

Spiral motion
of drilling
system

Crack in wall
surface

To prevent spiral motion and lateral motion Special
stabilization was designed

These holes were considered for escape of cuttings
Adding this type of stabilization decrease lateral movement; however, these holes
do not supply enough area for escape of cuttings

……Other bits and a stabilizer were designed and
cracks that appeared in each step led to
development of final drilling system and technical
drilling….

Final Bit

Final Bit

Final Bit

Final Bit

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

How the new designed bit act?

Masonry Wall

Rod

Escape line
Of cuttings
Masonry Wall

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

Conclusion
1. Rate of penetration with non-coring bits is high. However, these bits
are not as precise as coring bits. In spite of high precision coring bits
are not so fast due to several pull out of the bits for emptying the
cores.
2. If non-coring bits are used, as the size of TCs increases, the
deviation of the hole will increase. Larger cuttings lead to asymmetric
engagement of TC and cuttings and make a permanent change in the
axis of rotation.

Conclusion
3. Stabilizers are used to increase the accuracy and decrease the
deviation in drilling path. Although, it must be noted that they
increase air pressure on the surface of the holes and crack the
finishing.
4. The most important result of this study is the combination of coring
and non-coring bits. To stabilize the drilling path and decrease the
deviation, a guide is installed on the TC-Non-Coring bit instead of
stabilizers. On the whole, this drilling bit contains a TC Coring bit
which cores from the masonry walls. This bit penetrates through the
wall as a guide and prevents the bit from deviation and out of axis
rotation. In a short distance from the TC-Coring bit, TC Non-Coring bit
is installed. This bit crushes the cores and makes the cuttings ready for
being removed from the hole as dust. The smaller the cuttings are, the
lower air pressure is needed to remove them.

Conclusion
5. This newly invented bit could use for mining, oil and other
excavations as well.
6. Hydraulic drilling machines have a better performance
compared to SGZ Rotary machine because they are larger.
7. The drilling technique must be such that the bit pressure would
be minimum.

Conclusion
8. The brick type, mortar and the quality of bricking are
determining factors for setting the drilling speed and air pressure.
It seems that we can’t have exact quantities of such factors now;
however, an expert drilling operator may achieve this.

9. During drilling operation, the speed of rotation and air pressure
could be set by observing the size of cuttings. An expert can
minimize the size of cuttings by paying attention to it.

Thanks for your kind Attention


Slide 19

Perforating the masonry walls in
rehabilitation of masonry
Buildings using center core method
Alireza Mahdizadeh - Jamaledin Borzouie

Center core method is the good suggestion for retrofitting of
Historical masonry buildings due to non-destructive
construction.

Importance of Historical Buildings
Cultural Importance
Economy of tourists

Economic Impacts

Life loss ( Historical schools)

Large cost of renovation
after earthquake

Arg-e-Bam and Bam earthquake,2003
The largest adobe building in the world
The origins of Bam : 6th to 4th centuries BC

Before Bam Earthquake,2003

After Bam Earthquake,2003

Time needed for rebuild of this structure after damage of Bam earthquake :12 years
Total cost for rebuild : 120 million $

Before Bam Earthquake,2003

After Bam Earthquake,2003

Solution

Why Center core?
others
1%

concrete
2%
steel
8%

Large number of
masonry buildings
Masonry
89%

Non-destructive method

Without Evacuation

Steps

Problems

Perforating the
masonry walls

How to perforate masonry walls
without any cracks on wall
surface

Placing bars in
holes

Area, Distance, Number of bars

Placing grout
in holes

Properties of grout

the building was studied under the critical conditions
Very weak mortar

Strong bricks

Loose finishing of the wall
Wall thickness is at most
30 centimetres
selected school: Do Shahid
The building has 3 The
stories
Aged about 50 years

Parts of Drilling systems
Drilling Machine

Rod

Hydraulic

Rotary

Drilling
Rod transmits
machinethe
produces
rotatingthe
force
energy
to the stabilizer
for rotation
and
ofbit
the bit

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer
Stabilizer reduces the lateral movements
and bit shaking along the drilling path

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer

Bits

Bit penetrates through the depth and
determines the drilling path

Principle of design
4 boreholes (total 28 m height) were perforated in this project.
In each borehole, drilling technique, equipments and bits were
changed or design according to the damage in the wall surface .
After observation of these cracks the wall surface was
destructed; moreover, a new bit or stabilizer was designed
according to movement of bit on surface of bricks and other
observations ( air pressure, rotation of bit ...) to obtain the most
suitable ones.

Step 1: changing available Bits and Stabilizers
in drilling to obtain general vision for next step
Bit properties

Diamond
Non coring
D: 76 mm
Diamond
Coring
D: 76 mm

TC
Coring
D: 93mm

picture

Damage
Bit deviation due to large
contact surface with cement

How we deal with this
new
Cracks were observed In the
part of the wall due
problem? weakest
to high air pressure and lack
of mortar in the gap between
two bricks, the air flow pushes
the finishing and damages it
such that cuttings were
dispersed.

Bit properties

TC
Non coring
D: 93 mm

picture

Damage

Cracks appear due to weak
bricking

Good Suggestion for next step
TC
Non coring
D: 66mm

Finishing remains unhurt

Step 2: Designing new bits and stabilizers by
result of past drillings

TC
Non coring
D: 76 mm
TC 6 mm×6mm

New changes:
Increaseof TC dimension: 6 mm×6mm

New ways for exist of cuttings

Step 2: Designing new bits and stabilizers by
result of past drillings

Increase
dimension of
cuttings

A Cutting act
as a base

Spiral motion
of drilling
system

Crack in wall
surface

To prevent spiral motion and lateral motion Special
stabilization was designed

These holes were considered for escape of cuttings
Adding this type of stabilization decrease lateral movement; however, these holes
do not supply enough area for escape of cuttings

……Other bits and a stabilizer were designed and
cracks that appeared in each step led to
development of final drilling system and technical
drilling….

Final Bit

Final Bit

Final Bit

Final Bit

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

How the new designed bit act?

Masonry Wall

Rod

Escape line
Of cuttings
Masonry Wall

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

Conclusion
1. Rate of penetration with non-coring bits is high. However, these bits
are not as precise as coring bits. In spite of high precision coring bits
are not so fast due to several pull out of the bits for emptying the
cores.
2. If non-coring bits are used, as the size of TCs increases, the
deviation of the hole will increase. Larger cuttings lead to asymmetric
engagement of TC and cuttings and make a permanent change in the
axis of rotation.

Conclusion
3. Stabilizers are used to increase the accuracy and decrease the
deviation in drilling path. Although, it must be noted that they
increase air pressure on the surface of the holes and crack the
finishing.
4. The most important result of this study is the combination of coring
and non-coring bits. To stabilize the drilling path and decrease the
deviation, a guide is installed on the TC-Non-Coring bit instead of
stabilizers. On the whole, this drilling bit contains a TC Coring bit
which cores from the masonry walls. This bit penetrates through the
wall as a guide and prevents the bit from deviation and out of axis
rotation. In a short distance from the TC-Coring bit, TC Non-Coring bit
is installed. This bit crushes the cores and makes the cuttings ready for
being removed from the hole as dust. The smaller the cuttings are, the
lower air pressure is needed to remove them.

Conclusion
5. This newly invented bit could use for mining, oil and other
excavations as well.
6. Hydraulic drilling machines have a better performance
compared to SGZ Rotary machine because they are larger.
7. The drilling technique must be such that the bit pressure would
be minimum.

Conclusion
8. The brick type, mortar and the quality of bricking are
determining factors for setting the drilling speed and air pressure.
It seems that we can’t have exact quantities of such factors now;
however, an expert drilling operator may achieve this.

9. During drilling operation, the speed of rotation and air pressure
could be set by observing the size of cuttings. An expert can
minimize the size of cuttings by paying attention to it.

Thanks for your kind Attention


Slide 20

Perforating the masonry walls in
rehabilitation of masonry
Buildings using center core method
Alireza Mahdizadeh - Jamaledin Borzouie

Center core method is the good suggestion for retrofitting of
Historical masonry buildings due to non-destructive
construction.

Importance of Historical Buildings
Cultural Importance
Economy of tourists

Economic Impacts

Life loss ( Historical schools)

Large cost of renovation
after earthquake

Arg-e-Bam and Bam earthquake,2003
The largest adobe building in the world
The origins of Bam : 6th to 4th centuries BC

Before Bam Earthquake,2003

After Bam Earthquake,2003

Time needed for rebuild of this structure after damage of Bam earthquake :12 years
Total cost for rebuild : 120 million $

Before Bam Earthquake,2003

After Bam Earthquake,2003

Solution

Why Center core?
others
1%

concrete
2%
steel
8%

Large number of
masonry buildings
Masonry
89%

Non-destructive method

Without Evacuation

Steps

Problems

Perforating the
masonry walls

How to perforate masonry walls
without any cracks on wall
surface

Placing bars in
holes

Area, Distance, Number of bars

Placing grout
in holes

Properties of grout

the building was studied under the critical conditions
Very weak mortar

Strong bricks

Loose finishing of the wall
Wall thickness is at most
30 centimetres
selected school: Do Shahid
The building has 3 The
stories
Aged about 50 years

Parts of Drilling systems
Drilling Machine

Rod

Hydraulic

Rotary

Drilling
Rod transmits
machinethe
produces
rotatingthe
force
energy
to the stabilizer
for rotation
and
ofbit
the bit

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer
Stabilizer reduces the lateral movements
and bit shaking along the drilling path

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer

Bits

Bit penetrates through the depth and
determines the drilling path

Principle of design
4 boreholes (total 28 m height) were perforated in this project.
In each borehole, drilling technique, equipments and bits were
changed or design according to the damage in the wall surface .
After observation of these cracks the wall surface was
destructed; moreover, a new bit or stabilizer was designed
according to movement of bit on surface of bricks and other
observations ( air pressure, rotation of bit ...) to obtain the most
suitable ones.

Step 1: changing available Bits and Stabilizers
in drilling to obtain general vision for next step
Bit properties

Diamond
Non coring
D: 76 mm
Diamond
Coring
D: 76 mm

TC
Coring
D: 93mm

picture

Damage
Bit deviation due to large
contact surface with cement

How we deal with this
new
Cracks were observed In the
part of the wall due
problem? weakest
to high air pressure and lack
of mortar in the gap between
two bricks, the air flow pushes
the finishing and damages it
such that cuttings were
dispersed.

Bit properties

TC
Non coring
D: 93 mm

picture

Damage

Cracks appear due to weak
bricking

Good Suggestion for next step
TC
Non coring
D: 66mm

Finishing remains unhurt

Step 2: Designing new bits and stabilizers by
result of past drillings

TC
Non coring
D: 76 mm
TC 6 mm×6mm

New changes:
Increaseof TC dimension: 6 mm×6mm

New ways for exist of cuttings

Step 2: Designing new bits and stabilizers by
result of past drillings

Increase
dimension of
cuttings

A Cutting act
as a base

Spiral motion
of drilling
system

Crack in wall
surface

To prevent spiral motion and lateral motion Special
stabilization was designed

These holes were considered for escape of cuttings
Adding this type of stabilization decrease lateral movement; however, these holes
do not supply enough area for escape of cuttings

……Other bits and a stabilizer were designed and
cracks that appeared in each step led to
development of final drilling system and technical
drilling….

Final Bit

Final Bit

Final Bit

Final Bit

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

How the new designed bit act?

Masonry Wall

Rod

Escape line
Of cuttings
Masonry Wall

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

Conclusion
1. Rate of penetration with non-coring bits is high. However, these bits
are not as precise as coring bits. In spite of high precision coring bits
are not so fast due to several pull out of the bits for emptying the
cores.
2. If non-coring bits are used, as the size of TCs increases, the
deviation of the hole will increase. Larger cuttings lead to asymmetric
engagement of TC and cuttings and make a permanent change in the
axis of rotation.

Conclusion
3. Stabilizers are used to increase the accuracy and decrease the
deviation in drilling path. Although, it must be noted that they
increase air pressure on the surface of the holes and crack the
finishing.
4. The most important result of this study is the combination of coring
and non-coring bits. To stabilize the drilling path and decrease the
deviation, a guide is installed on the TC-Non-Coring bit instead of
stabilizers. On the whole, this drilling bit contains a TC Coring bit
which cores from the masonry walls. This bit penetrates through the
wall as a guide and prevents the bit from deviation and out of axis
rotation. In a short distance from the TC-Coring bit, TC Non-Coring bit
is installed. This bit crushes the cores and makes the cuttings ready for
being removed from the hole as dust. The smaller the cuttings are, the
lower air pressure is needed to remove them.

Conclusion
5. This newly invented bit could use for mining, oil and other
excavations as well.
6. Hydraulic drilling machines have a better performance
compared to SGZ Rotary machine because they are larger.
7. The drilling technique must be such that the bit pressure would
be minimum.

Conclusion
8. The brick type, mortar and the quality of bricking are
determining factors for setting the drilling speed and air pressure.
It seems that we can’t have exact quantities of such factors now;
however, an expert drilling operator may achieve this.

9. During drilling operation, the speed of rotation and air pressure
could be set by observing the size of cuttings. An expert can
minimize the size of cuttings by paying attention to it.

Thanks for your kind Attention


Slide 21

Perforating the masonry walls in
rehabilitation of masonry
Buildings using center core method
Alireza Mahdizadeh - Jamaledin Borzouie

Center core method is the good suggestion for retrofitting of
Historical masonry buildings due to non-destructive
construction.

Importance of Historical Buildings
Cultural Importance
Economy of tourists

Economic Impacts

Life loss ( Historical schools)

Large cost of renovation
after earthquake

Arg-e-Bam and Bam earthquake,2003
The largest adobe building in the world
The origins of Bam : 6th to 4th centuries BC

Before Bam Earthquake,2003

After Bam Earthquake,2003

Time needed for rebuild of this structure after damage of Bam earthquake :12 years
Total cost for rebuild : 120 million $

Before Bam Earthquake,2003

After Bam Earthquake,2003

Solution

Why Center core?
others
1%

concrete
2%
steel
8%

Large number of
masonry buildings
Masonry
89%

Non-destructive method

Without Evacuation

Steps

Problems

Perforating the
masonry walls

How to perforate masonry walls
without any cracks on wall
surface

Placing bars in
holes

Area, Distance, Number of bars

Placing grout
in holes

Properties of grout

the building was studied under the critical conditions
Very weak mortar

Strong bricks

Loose finishing of the wall
Wall thickness is at most
30 centimetres
selected school: Do Shahid
The building has 3 The
stories
Aged about 50 years

Parts of Drilling systems
Drilling Machine

Rod

Hydraulic

Rotary

Drilling
Rod transmits
machinethe
produces
rotatingthe
force
energy
to the stabilizer
for rotation
and
ofbit
the bit

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer
Stabilizer reduces the lateral movements
and bit shaking along the drilling path

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer

Bits

Bit penetrates through the depth and
determines the drilling path

Principle of design
4 boreholes (total 28 m height) were perforated in this project.
In each borehole, drilling technique, equipments and bits were
changed or design according to the damage in the wall surface .
After observation of these cracks the wall surface was
destructed; moreover, a new bit or stabilizer was designed
according to movement of bit on surface of bricks and other
observations ( air pressure, rotation of bit ...) to obtain the most
suitable ones.

Step 1: changing available Bits and Stabilizers
in drilling to obtain general vision for next step
Bit properties

Diamond
Non coring
D: 76 mm
Diamond
Coring
D: 76 mm

TC
Coring
D: 93mm

picture

Damage
Bit deviation due to large
contact surface with cement

How we deal with this
new
Cracks were observed In the
part of the wall due
problem? weakest
to high air pressure and lack
of mortar in the gap between
two bricks, the air flow pushes
the finishing and damages it
such that cuttings were
dispersed.

Bit properties

TC
Non coring
D: 93 mm

picture

Damage

Cracks appear due to weak
bricking

Good Suggestion for next step
TC
Non coring
D: 66mm

Finishing remains unhurt

Step 2: Designing new bits and stabilizers by
result of past drillings

TC
Non coring
D: 76 mm
TC 6 mm×6mm

New changes:
Increaseof TC dimension: 6 mm×6mm

New ways for exist of cuttings

Step 2: Designing new bits and stabilizers by
result of past drillings

Increase
dimension of
cuttings

A Cutting act
as a base

Spiral motion
of drilling
system

Crack in wall
surface

To prevent spiral motion and lateral motion Special
stabilization was designed

These holes were considered for escape of cuttings
Adding this type of stabilization decrease lateral movement; however, these holes
do not supply enough area for escape of cuttings

……Other bits and a stabilizer were designed and
cracks that appeared in each step led to
development of final drilling system and technical
drilling….

Final Bit

Final Bit

Final Bit

Final Bit

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

How the new designed bit act?

Masonry Wall

Rod

Escape line
Of cuttings
Masonry Wall

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

Conclusion
1. Rate of penetration with non-coring bits is high. However, these bits
are not as precise as coring bits. In spite of high precision coring bits
are not so fast due to several pull out of the bits for emptying the
cores.
2. If non-coring bits are used, as the size of TCs increases, the
deviation of the hole will increase. Larger cuttings lead to asymmetric
engagement of TC and cuttings and make a permanent change in the
axis of rotation.

Conclusion
3. Stabilizers are used to increase the accuracy and decrease the
deviation in drilling path. Although, it must be noted that they
increase air pressure on the surface of the holes and crack the
finishing.
4. The most important result of this study is the combination of coring
and non-coring bits. To stabilize the drilling path and decrease the
deviation, a guide is installed on the TC-Non-Coring bit instead of
stabilizers. On the whole, this drilling bit contains a TC Coring bit
which cores from the masonry walls. This bit penetrates through the
wall as a guide and prevents the bit from deviation and out of axis
rotation. In a short distance from the TC-Coring bit, TC Non-Coring bit
is installed. This bit crushes the cores and makes the cuttings ready for
being removed from the hole as dust. The smaller the cuttings are, the
lower air pressure is needed to remove them.

Conclusion
5. This newly invented bit could use for mining, oil and other
excavations as well.
6. Hydraulic drilling machines have a better performance
compared to SGZ Rotary machine because they are larger.
7. The drilling technique must be such that the bit pressure would
be minimum.

Conclusion
8. The brick type, mortar and the quality of bricking are
determining factors for setting the drilling speed and air pressure.
It seems that we can’t have exact quantities of such factors now;
however, an expert drilling operator may achieve this.

9. During drilling operation, the speed of rotation and air pressure
could be set by observing the size of cuttings. An expert can
minimize the size of cuttings by paying attention to it.

Thanks for your kind Attention


Slide 22

Perforating the masonry walls in
rehabilitation of masonry
Buildings using center core method
Alireza Mahdizadeh - Jamaledin Borzouie

Center core method is the good suggestion for retrofitting of
Historical masonry buildings due to non-destructive
construction.

Importance of Historical Buildings
Cultural Importance
Economy of tourists

Economic Impacts

Life loss ( Historical schools)

Large cost of renovation
after earthquake

Arg-e-Bam and Bam earthquake,2003
The largest adobe building in the world
The origins of Bam : 6th to 4th centuries BC

Before Bam Earthquake,2003

After Bam Earthquake,2003

Time needed for rebuild of this structure after damage of Bam earthquake :12 years
Total cost for rebuild : 120 million $

Before Bam Earthquake,2003

After Bam Earthquake,2003

Solution

Why Center core?
others
1%

concrete
2%
steel
8%

Large number of
masonry buildings
Masonry
89%

Non-destructive method

Without Evacuation

Steps

Problems

Perforating the
masonry walls

How to perforate masonry walls
without any cracks on wall
surface

Placing bars in
holes

Area, Distance, Number of bars

Placing grout
in holes

Properties of grout

the building was studied under the critical conditions
Very weak mortar

Strong bricks

Loose finishing of the wall
Wall thickness is at most
30 centimetres
selected school: Do Shahid
The building has 3 The
stories
Aged about 50 years

Parts of Drilling systems
Drilling Machine

Rod

Hydraulic

Rotary

Drilling
Rod transmits
machinethe
produces
rotatingthe
force
energy
to the stabilizer
for rotation
and
ofbit
the bit

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer
Stabilizer reduces the lateral movements
and bit shaking along the drilling path

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer

Bits

Bit penetrates through the depth and
determines the drilling path

Principle of design
4 boreholes (total 28 m height) were perforated in this project.
In each borehole, drilling technique, equipments and bits were
changed or design according to the damage in the wall surface .
After observation of these cracks the wall surface was
destructed; moreover, a new bit or stabilizer was designed
according to movement of bit on surface of bricks and other
observations ( air pressure, rotation of bit ...) to obtain the most
suitable ones.

Step 1: changing available Bits and Stabilizers
in drilling to obtain general vision for next step
Bit properties

Diamond
Non coring
D: 76 mm
Diamond
Coring
D: 76 mm

TC
Coring
D: 93mm

picture

Damage
Bit deviation due to large
contact surface with cement

How we deal with this
new
Cracks were observed In the
part of the wall due
problem? weakest
to high air pressure and lack
of mortar in the gap between
two bricks, the air flow pushes
the finishing and damages it
such that cuttings were
dispersed.

Bit properties

TC
Non coring
D: 93 mm

picture

Damage

Cracks appear due to weak
bricking

Good Suggestion for next step
TC
Non coring
D: 66mm

Finishing remains unhurt

Step 2: Designing new bits and stabilizers by
result of past drillings

TC
Non coring
D: 76 mm
TC 6 mm×6mm

New changes:
Increaseof TC dimension: 6 mm×6mm

New ways for exist of cuttings

Step 2: Designing new bits and stabilizers by
result of past drillings

Increase
dimension of
cuttings

A Cutting act
as a base

Spiral motion
of drilling
system

Crack in wall
surface

To prevent spiral motion and lateral motion Special
stabilization was designed

These holes were considered for escape of cuttings
Adding this type of stabilization decrease lateral movement; however, these holes
do not supply enough area for escape of cuttings

……Other bits and a stabilizer were designed and
cracks that appeared in each step led to
development of final drilling system and technical
drilling….

Final Bit

Final Bit

Final Bit

Final Bit

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

How the new designed bit act?

Masonry Wall

Rod

Escape line
Of cuttings
Masonry Wall

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

Conclusion
1. Rate of penetration with non-coring bits is high. However, these bits
are not as precise as coring bits. In spite of high precision coring bits
are not so fast due to several pull out of the bits for emptying the
cores.
2. If non-coring bits are used, as the size of TCs increases, the
deviation of the hole will increase. Larger cuttings lead to asymmetric
engagement of TC and cuttings and make a permanent change in the
axis of rotation.

Conclusion
3. Stabilizers are used to increase the accuracy and decrease the
deviation in drilling path. Although, it must be noted that they
increase air pressure on the surface of the holes and crack the
finishing.
4. The most important result of this study is the combination of coring
and non-coring bits. To stabilize the drilling path and decrease the
deviation, a guide is installed on the TC-Non-Coring bit instead of
stabilizers. On the whole, this drilling bit contains a TC Coring bit
which cores from the masonry walls. This bit penetrates through the
wall as a guide and prevents the bit from deviation and out of axis
rotation. In a short distance from the TC-Coring bit, TC Non-Coring bit
is installed. This bit crushes the cores and makes the cuttings ready for
being removed from the hole as dust. The smaller the cuttings are, the
lower air pressure is needed to remove them.

Conclusion
5. This newly invented bit could use for mining, oil and other
excavations as well.
6. Hydraulic drilling machines have a better performance
compared to SGZ Rotary machine because they are larger.
7. The drilling technique must be such that the bit pressure would
be minimum.

Conclusion
8. The brick type, mortar and the quality of bricking are
determining factors for setting the drilling speed and air pressure.
It seems that we can’t have exact quantities of such factors now;
however, an expert drilling operator may achieve this.

9. During drilling operation, the speed of rotation and air pressure
could be set by observing the size of cuttings. An expert can
minimize the size of cuttings by paying attention to it.

Thanks for your kind Attention


Slide 23

Perforating the masonry walls in
rehabilitation of masonry
Buildings using center core method
Alireza Mahdizadeh - Jamaledin Borzouie

Center core method is the good suggestion for retrofitting of
Historical masonry buildings due to non-destructive
construction.

Importance of Historical Buildings
Cultural Importance
Economy of tourists

Economic Impacts

Life loss ( Historical schools)

Large cost of renovation
after earthquake

Arg-e-Bam and Bam earthquake,2003
The largest adobe building in the world
The origins of Bam : 6th to 4th centuries BC

Before Bam Earthquake,2003

After Bam Earthquake,2003

Time needed for rebuild of this structure after damage of Bam earthquake :12 years
Total cost for rebuild : 120 million $

Before Bam Earthquake,2003

After Bam Earthquake,2003

Solution

Why Center core?
others
1%

concrete
2%
steel
8%

Large number of
masonry buildings
Masonry
89%

Non-destructive method

Without Evacuation

Steps

Problems

Perforating the
masonry walls

How to perforate masonry walls
without any cracks on wall
surface

Placing bars in
holes

Area, Distance, Number of bars

Placing grout
in holes

Properties of grout

the building was studied under the critical conditions
Very weak mortar

Strong bricks

Loose finishing of the wall
Wall thickness is at most
30 centimetres
selected school: Do Shahid
The building has 3 The
stories
Aged about 50 years

Parts of Drilling systems
Drilling Machine

Rod

Hydraulic

Rotary

Drilling
Rod transmits
machinethe
produces
rotatingthe
force
energy
to the stabilizer
for rotation
and
ofbit
the bit

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer
Stabilizer reduces the lateral movements
and bit shaking along the drilling path

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer

Bits

Bit penetrates through the depth and
determines the drilling path

Principle of design
4 boreholes (total 28 m height) were perforated in this project.
In each borehole, drilling technique, equipments and bits were
changed or design according to the damage in the wall surface .
After observation of these cracks the wall surface was
destructed; moreover, a new bit or stabilizer was designed
according to movement of bit on surface of bricks and other
observations ( air pressure, rotation of bit ...) to obtain the most
suitable ones.

Step 1: changing available Bits and Stabilizers
in drilling to obtain general vision for next step
Bit properties

Diamond
Non coring
D: 76 mm
Diamond
Coring
D: 76 mm

TC
Coring
D: 93mm

picture

Damage
Bit deviation due to large
contact surface with cement

How we deal with this
new
Cracks were observed In the
part of the wall due
problem? weakest
to high air pressure and lack
of mortar in the gap between
two bricks, the air flow pushes
the finishing and damages it
such that cuttings were
dispersed.

Bit properties

TC
Non coring
D: 93 mm

picture

Damage

Cracks appear due to weak
bricking

Good Suggestion for next step
TC
Non coring
D: 66mm

Finishing remains unhurt

Step 2: Designing new bits and stabilizers by
result of past drillings

TC
Non coring
D: 76 mm
TC 6 mm×6mm

New changes:
Increaseof TC dimension: 6 mm×6mm

New ways for exist of cuttings

Step 2: Designing new bits and stabilizers by
result of past drillings

Increase
dimension of
cuttings

A Cutting act
as a base

Spiral motion
of drilling
system

Crack in wall
surface

To prevent spiral motion and lateral motion Special
stabilization was designed

These holes were considered for escape of cuttings
Adding this type of stabilization decrease lateral movement; however, these holes
do not supply enough area for escape of cuttings

……Other bits and a stabilizer were designed and
cracks that appeared in each step led to
development of final drilling system and technical
drilling….

Final Bit

Final Bit

Final Bit

Final Bit

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

How the new designed bit act?

Masonry Wall

Rod

Escape line
Of cuttings
Masonry Wall

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

Conclusion
1. Rate of penetration with non-coring bits is high. However, these bits
are not as precise as coring bits. In spite of high precision coring bits
are not so fast due to several pull out of the bits for emptying the
cores.
2. If non-coring bits are used, as the size of TCs increases, the
deviation of the hole will increase. Larger cuttings lead to asymmetric
engagement of TC and cuttings and make a permanent change in the
axis of rotation.

Conclusion
3. Stabilizers are used to increase the accuracy and decrease the
deviation in drilling path. Although, it must be noted that they
increase air pressure on the surface of the holes and crack the
finishing.
4. The most important result of this study is the combination of coring
and non-coring bits. To stabilize the drilling path and decrease the
deviation, a guide is installed on the TC-Non-Coring bit instead of
stabilizers. On the whole, this drilling bit contains a TC Coring bit
which cores from the masonry walls. This bit penetrates through the
wall as a guide and prevents the bit from deviation and out of axis
rotation. In a short distance from the TC-Coring bit, TC Non-Coring bit
is installed. This bit crushes the cores and makes the cuttings ready for
being removed from the hole as dust. The smaller the cuttings are, the
lower air pressure is needed to remove them.

Conclusion
5. This newly invented bit could use for mining, oil and other
excavations as well.
6. Hydraulic drilling machines have a better performance
compared to SGZ Rotary machine because they are larger.
7. The drilling technique must be such that the bit pressure would
be minimum.

Conclusion
8. The brick type, mortar and the quality of bricking are
determining factors for setting the drilling speed and air pressure.
It seems that we can’t have exact quantities of such factors now;
however, an expert drilling operator may achieve this.

9. During drilling operation, the speed of rotation and air pressure
could be set by observing the size of cuttings. An expert can
minimize the size of cuttings by paying attention to it.

Thanks for your kind Attention


Slide 24

Perforating the masonry walls in
rehabilitation of masonry
Buildings using center core method
Alireza Mahdizadeh - Jamaledin Borzouie

Center core method is the good suggestion for retrofitting of
Historical masonry buildings due to non-destructive
construction.

Importance of Historical Buildings
Cultural Importance
Economy of tourists

Economic Impacts

Life loss ( Historical schools)

Large cost of renovation
after earthquake

Arg-e-Bam and Bam earthquake,2003
The largest adobe building in the world
The origins of Bam : 6th to 4th centuries BC

Before Bam Earthquake,2003

After Bam Earthquake,2003

Time needed for rebuild of this structure after damage of Bam earthquake :12 years
Total cost for rebuild : 120 million $

Before Bam Earthquake,2003

After Bam Earthquake,2003

Solution

Why Center core?
others
1%

concrete
2%
steel
8%

Large number of
masonry buildings
Masonry
89%

Non-destructive method

Without Evacuation

Steps

Problems

Perforating the
masonry walls

How to perforate masonry walls
without any cracks on wall
surface

Placing bars in
holes

Area, Distance, Number of bars

Placing grout
in holes

Properties of grout

the building was studied under the critical conditions
Very weak mortar

Strong bricks

Loose finishing of the wall
Wall thickness is at most
30 centimetres
selected school: Do Shahid
The building has 3 The
stories
Aged about 50 years

Parts of Drilling systems
Drilling Machine

Rod

Hydraulic

Rotary

Drilling
Rod transmits
machinethe
produces
rotatingthe
force
energy
to the stabilizer
for rotation
and
ofbit
the bit

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer
Stabilizer reduces the lateral movements
and bit shaking along the drilling path

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer

Bits

Bit penetrates through the depth and
determines the drilling path

Principle of design
4 boreholes (total 28 m height) were perforated in this project.
In each borehole, drilling technique, equipments and bits were
changed or design according to the damage in the wall surface .
After observation of these cracks the wall surface was
destructed; moreover, a new bit or stabilizer was designed
according to movement of bit on surface of bricks and other
observations ( air pressure, rotation of bit ...) to obtain the most
suitable ones.

Step 1: changing available Bits and Stabilizers
in drilling to obtain general vision for next step
Bit properties

Diamond
Non coring
D: 76 mm
Diamond
Coring
D: 76 mm

TC
Coring
D: 93mm

picture

Damage
Bit deviation due to large
contact surface with cement

How we deal with this
new
Cracks were observed In the
part of the wall due
problem? weakest
to high air pressure and lack
of mortar in the gap between
two bricks, the air flow pushes
the finishing and damages it
such that cuttings were
dispersed.

Bit properties

TC
Non coring
D: 93 mm

picture

Damage

Cracks appear due to weak
bricking

Good Suggestion for next step
TC
Non coring
D: 66mm

Finishing remains unhurt

Step 2: Designing new bits and stabilizers by
result of past drillings

TC
Non coring
D: 76 mm
TC 6 mm×6mm

New changes:
Increaseof TC dimension: 6 mm×6mm

New ways for exist of cuttings

Step 2: Designing new bits and stabilizers by
result of past drillings

Increase
dimension of
cuttings

A Cutting act
as a base

Spiral motion
of drilling
system

Crack in wall
surface

To prevent spiral motion and lateral motion Special
stabilization was designed

These holes were considered for escape of cuttings
Adding this type of stabilization decrease lateral movement; however, these holes
do not supply enough area for escape of cuttings

……Other bits and a stabilizer were designed and
cracks that appeared in each step led to
development of final drilling system and technical
drilling….

Final Bit

Final Bit

Final Bit

Final Bit

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

How the new designed bit act?

Masonry Wall

Rod

Escape line
Of cuttings
Masonry Wall

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

Conclusion
1. Rate of penetration with non-coring bits is high. However, these bits
are not as precise as coring bits. In spite of high precision coring bits
are not so fast due to several pull out of the bits for emptying the
cores.
2. If non-coring bits are used, as the size of TCs increases, the
deviation of the hole will increase. Larger cuttings lead to asymmetric
engagement of TC and cuttings and make a permanent change in the
axis of rotation.

Conclusion
3. Stabilizers are used to increase the accuracy and decrease the
deviation in drilling path. Although, it must be noted that they
increase air pressure on the surface of the holes and crack the
finishing.
4. The most important result of this study is the combination of coring
and non-coring bits. To stabilize the drilling path and decrease the
deviation, a guide is installed on the TC-Non-Coring bit instead of
stabilizers. On the whole, this drilling bit contains a TC Coring bit
which cores from the masonry walls. This bit penetrates through the
wall as a guide and prevents the bit from deviation and out of axis
rotation. In a short distance from the TC-Coring bit, TC Non-Coring bit
is installed. This bit crushes the cores and makes the cuttings ready for
being removed from the hole as dust. The smaller the cuttings are, the
lower air pressure is needed to remove them.

Conclusion
5. This newly invented bit could use for mining, oil and other
excavations as well.
6. Hydraulic drilling machines have a better performance
compared to SGZ Rotary machine because they are larger.
7. The drilling technique must be such that the bit pressure would
be minimum.

Conclusion
8. The brick type, mortar and the quality of bricking are
determining factors for setting the drilling speed and air pressure.
It seems that we can’t have exact quantities of such factors now;
however, an expert drilling operator may achieve this.

9. During drilling operation, the speed of rotation and air pressure
could be set by observing the size of cuttings. An expert can
minimize the size of cuttings by paying attention to it.

Thanks for your kind Attention


Slide 25

Perforating the masonry walls in
rehabilitation of masonry
Buildings using center core method
Alireza Mahdizadeh - Jamaledin Borzouie

Center core method is the good suggestion for retrofitting of
Historical masonry buildings due to non-destructive
construction.

Importance of Historical Buildings
Cultural Importance
Economy of tourists

Economic Impacts

Life loss ( Historical schools)

Large cost of renovation
after earthquake

Arg-e-Bam and Bam earthquake,2003
The largest adobe building in the world
The origins of Bam : 6th to 4th centuries BC

Before Bam Earthquake,2003

After Bam Earthquake,2003

Time needed for rebuild of this structure after damage of Bam earthquake :12 years
Total cost for rebuild : 120 million $

Before Bam Earthquake,2003

After Bam Earthquake,2003

Solution

Why Center core?
others
1%

concrete
2%
steel
8%

Large number of
masonry buildings
Masonry
89%

Non-destructive method

Without Evacuation

Steps

Problems

Perforating the
masonry walls

How to perforate masonry walls
without any cracks on wall
surface

Placing bars in
holes

Area, Distance, Number of bars

Placing grout
in holes

Properties of grout

the building was studied under the critical conditions
Very weak mortar

Strong bricks

Loose finishing of the wall
Wall thickness is at most
30 centimetres
selected school: Do Shahid
The building has 3 The
stories
Aged about 50 years

Parts of Drilling systems
Drilling Machine

Rod

Hydraulic

Rotary

Drilling
Rod transmits
machinethe
produces
rotatingthe
force
energy
to the stabilizer
for rotation
and
ofbit
the bit

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer
Stabilizer reduces the lateral movements
and bit shaking along the drilling path

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer

Bits

Bit penetrates through the depth and
determines the drilling path

Principle of design
4 boreholes (total 28 m height) were perforated in this project.
In each borehole, drilling technique, equipments and bits were
changed or design according to the damage in the wall surface .
After observation of these cracks the wall surface was
destructed; moreover, a new bit or stabilizer was designed
according to movement of bit on surface of bricks and other
observations ( air pressure, rotation of bit ...) to obtain the most
suitable ones.

Step 1: changing available Bits and Stabilizers
in drilling to obtain general vision for next step
Bit properties

Diamond
Non coring
D: 76 mm
Diamond
Coring
D: 76 mm

TC
Coring
D: 93mm

picture

Damage
Bit deviation due to large
contact surface with cement

How we deal with this
new
Cracks were observed In the
part of the wall due
problem? weakest
to high air pressure and lack
of mortar in the gap between
two bricks, the air flow pushes
the finishing and damages it
such that cuttings were
dispersed.

Bit properties

TC
Non coring
D: 93 mm

picture

Damage

Cracks appear due to weak
bricking

Good Suggestion for next step
TC
Non coring
D: 66mm

Finishing remains unhurt

Step 2: Designing new bits and stabilizers by
result of past drillings

TC
Non coring
D: 76 mm
TC 6 mm×6mm

New changes:
Increaseof TC dimension: 6 mm×6mm

New ways for exist of cuttings

Step 2: Designing new bits and stabilizers by
result of past drillings

Increase
dimension of
cuttings

A Cutting act
as a base

Spiral motion
of drilling
system

Crack in wall
surface

To prevent spiral motion and lateral motion Special
stabilization was designed

These holes were considered for escape of cuttings
Adding this type of stabilization decrease lateral movement; however, these holes
do not supply enough area for escape of cuttings

……Other bits and a stabilizer were designed and
cracks that appeared in each step led to
development of final drilling system and technical
drilling….

Final Bit

Final Bit

Final Bit

Final Bit

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

How the new designed bit act?

Masonry Wall

Rod

Escape line
Of cuttings
Masonry Wall

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

Conclusion
1. Rate of penetration with non-coring bits is high. However, these bits
are not as precise as coring bits. In spite of high precision coring bits
are not so fast due to several pull out of the bits for emptying the
cores.
2. If non-coring bits are used, as the size of TCs increases, the
deviation of the hole will increase. Larger cuttings lead to asymmetric
engagement of TC and cuttings and make a permanent change in the
axis of rotation.

Conclusion
3. Stabilizers are used to increase the accuracy and decrease the
deviation in drilling path. Although, it must be noted that they
increase air pressure on the surface of the holes and crack the
finishing.
4. The most important result of this study is the combination of coring
and non-coring bits. To stabilize the drilling path and decrease the
deviation, a guide is installed on the TC-Non-Coring bit instead of
stabilizers. On the whole, this drilling bit contains a TC Coring bit
which cores from the masonry walls. This bit penetrates through the
wall as a guide and prevents the bit from deviation and out of axis
rotation. In a short distance from the TC-Coring bit, TC Non-Coring bit
is installed. This bit crushes the cores and makes the cuttings ready for
being removed from the hole as dust. The smaller the cuttings are, the
lower air pressure is needed to remove them.

Conclusion
5. This newly invented bit could use for mining, oil and other
excavations as well.
6. Hydraulic drilling machines have a better performance
compared to SGZ Rotary machine because they are larger.
7. The drilling technique must be such that the bit pressure would
be minimum.

Conclusion
8. The brick type, mortar and the quality of bricking are
determining factors for setting the drilling speed and air pressure.
It seems that we can’t have exact quantities of such factors now;
however, an expert drilling operator may achieve this.

9. During drilling operation, the speed of rotation and air pressure
could be set by observing the size of cuttings. An expert can
minimize the size of cuttings by paying attention to it.

Thanks for your kind Attention


Slide 26

Perforating the masonry walls in
rehabilitation of masonry
Buildings using center core method
Alireza Mahdizadeh - Jamaledin Borzouie

Center core method is the good suggestion for retrofitting of
Historical masonry buildings due to non-destructive
construction.

Importance of Historical Buildings
Cultural Importance
Economy of tourists

Economic Impacts

Life loss ( Historical schools)

Large cost of renovation
after earthquake

Arg-e-Bam and Bam earthquake,2003
The largest adobe building in the world
The origins of Bam : 6th to 4th centuries BC

Before Bam Earthquake,2003

After Bam Earthquake,2003

Time needed for rebuild of this structure after damage of Bam earthquake :12 years
Total cost for rebuild : 120 million $

Before Bam Earthquake,2003

After Bam Earthquake,2003

Solution

Why Center core?
others
1%

concrete
2%
steel
8%

Large number of
masonry buildings
Masonry
89%

Non-destructive method

Without Evacuation

Steps

Problems

Perforating the
masonry walls

How to perforate masonry walls
without any cracks on wall
surface

Placing bars in
holes

Area, Distance, Number of bars

Placing grout
in holes

Properties of grout

the building was studied under the critical conditions
Very weak mortar

Strong bricks

Loose finishing of the wall
Wall thickness is at most
30 centimetres
selected school: Do Shahid
The building has 3 The
stories
Aged about 50 years

Parts of Drilling systems
Drilling Machine

Rod

Hydraulic

Rotary

Drilling
Rod transmits
machinethe
produces
rotatingthe
force
energy
to the stabilizer
for rotation
and
ofbit
the bit

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer
Stabilizer reduces the lateral movements
and bit shaking along the drilling path

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer

Bits

Bit penetrates through the depth and
determines the drilling path

Principle of design
4 boreholes (total 28 m height) were perforated in this project.
In each borehole, drilling technique, equipments and bits were
changed or design according to the damage in the wall surface .
After observation of these cracks the wall surface was
destructed; moreover, a new bit or stabilizer was designed
according to movement of bit on surface of bricks and other
observations ( air pressure, rotation of bit ...) to obtain the most
suitable ones.

Step 1: changing available Bits and Stabilizers
in drilling to obtain general vision for next step
Bit properties

Diamond
Non coring
D: 76 mm
Diamond
Coring
D: 76 mm

TC
Coring
D: 93mm

picture

Damage
Bit deviation due to large
contact surface with cement

How we deal with this
new
Cracks were observed In the
part of the wall due
problem? weakest
to high air pressure and lack
of mortar in the gap between
two bricks, the air flow pushes
the finishing and damages it
such that cuttings were
dispersed.

Bit properties

TC
Non coring
D: 93 mm

picture

Damage

Cracks appear due to weak
bricking

Good Suggestion for next step
TC
Non coring
D: 66mm

Finishing remains unhurt

Step 2: Designing new bits and stabilizers by
result of past drillings

TC
Non coring
D: 76 mm
TC 6 mm×6mm

New changes:
Increaseof TC dimension: 6 mm×6mm

New ways for exist of cuttings

Step 2: Designing new bits and stabilizers by
result of past drillings

Increase
dimension of
cuttings

A Cutting act
as a base

Spiral motion
of drilling
system

Crack in wall
surface

To prevent spiral motion and lateral motion Special
stabilization was designed

These holes were considered for escape of cuttings
Adding this type of stabilization decrease lateral movement; however, these holes
do not supply enough area for escape of cuttings

……Other bits and a stabilizer were designed and
cracks that appeared in each step led to
development of final drilling system and technical
drilling….

Final Bit

Final Bit

Final Bit

Final Bit

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

How the new designed bit act?

Masonry Wall

Rod

Escape line
Of cuttings
Masonry Wall

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

Conclusion
1. Rate of penetration with non-coring bits is high. However, these bits
are not as precise as coring bits. In spite of high precision coring bits
are not so fast due to several pull out of the bits for emptying the
cores.
2. If non-coring bits are used, as the size of TCs increases, the
deviation of the hole will increase. Larger cuttings lead to asymmetric
engagement of TC and cuttings and make a permanent change in the
axis of rotation.

Conclusion
3. Stabilizers are used to increase the accuracy and decrease the
deviation in drilling path. Although, it must be noted that they
increase air pressure on the surface of the holes and crack the
finishing.
4. The most important result of this study is the combination of coring
and non-coring bits. To stabilize the drilling path and decrease the
deviation, a guide is installed on the TC-Non-Coring bit instead of
stabilizers. On the whole, this drilling bit contains a TC Coring bit
which cores from the masonry walls. This bit penetrates through the
wall as a guide and prevents the bit from deviation and out of axis
rotation. In a short distance from the TC-Coring bit, TC Non-Coring bit
is installed. This bit crushes the cores and makes the cuttings ready for
being removed from the hole as dust. The smaller the cuttings are, the
lower air pressure is needed to remove them.

Conclusion
5. This newly invented bit could use for mining, oil and other
excavations as well.
6. Hydraulic drilling machines have a better performance
compared to SGZ Rotary machine because they are larger.
7. The drilling technique must be such that the bit pressure would
be minimum.

Conclusion
8. The brick type, mortar and the quality of bricking are
determining factors for setting the drilling speed and air pressure.
It seems that we can’t have exact quantities of such factors now;
however, an expert drilling operator may achieve this.

9. During drilling operation, the speed of rotation and air pressure
could be set by observing the size of cuttings. An expert can
minimize the size of cuttings by paying attention to it.

Thanks for your kind Attention


Slide 27

Perforating the masonry walls in
rehabilitation of masonry
Buildings using center core method
Alireza Mahdizadeh - Jamaledin Borzouie

Center core method is the good suggestion for retrofitting of
Historical masonry buildings due to non-destructive
construction.

Importance of Historical Buildings
Cultural Importance
Economy of tourists

Economic Impacts

Life loss ( Historical schools)

Large cost of renovation
after earthquake

Arg-e-Bam and Bam earthquake,2003
The largest adobe building in the world
The origins of Bam : 6th to 4th centuries BC

Before Bam Earthquake,2003

After Bam Earthquake,2003

Time needed for rebuild of this structure after damage of Bam earthquake :12 years
Total cost for rebuild : 120 million $

Before Bam Earthquake,2003

After Bam Earthquake,2003

Solution

Why Center core?
others
1%

concrete
2%
steel
8%

Large number of
masonry buildings
Masonry
89%

Non-destructive method

Without Evacuation

Steps

Problems

Perforating the
masonry walls

How to perforate masonry walls
without any cracks on wall
surface

Placing bars in
holes

Area, Distance, Number of bars

Placing grout
in holes

Properties of grout

the building was studied under the critical conditions
Very weak mortar

Strong bricks

Loose finishing of the wall
Wall thickness is at most
30 centimetres
selected school: Do Shahid
The building has 3 The
stories
Aged about 50 years

Parts of Drilling systems
Drilling Machine

Rod

Hydraulic

Rotary

Drilling
Rod transmits
machinethe
produces
rotatingthe
force
energy
to the stabilizer
for rotation
and
ofbit
the bit

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer
Stabilizer reduces the lateral movements
and bit shaking along the drilling path

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer

Bits

Bit penetrates through the depth and
determines the drilling path

Principle of design
4 boreholes (total 28 m height) were perforated in this project.
In each borehole, drilling technique, equipments and bits were
changed or design according to the damage in the wall surface .
After observation of these cracks the wall surface was
destructed; moreover, a new bit or stabilizer was designed
according to movement of bit on surface of bricks and other
observations ( air pressure, rotation of bit ...) to obtain the most
suitable ones.

Step 1: changing available Bits and Stabilizers
in drilling to obtain general vision for next step
Bit properties

Diamond
Non coring
D: 76 mm
Diamond
Coring
D: 76 mm

TC
Coring
D: 93mm

picture

Damage
Bit deviation due to large
contact surface with cement

How we deal with this
new
Cracks were observed In the
part of the wall due
problem? weakest
to high air pressure and lack
of mortar in the gap between
two bricks, the air flow pushes
the finishing and damages it
such that cuttings were
dispersed.

Bit properties

TC
Non coring
D: 93 mm

picture

Damage

Cracks appear due to weak
bricking

Good Suggestion for next step
TC
Non coring
D: 66mm

Finishing remains unhurt

Step 2: Designing new bits and stabilizers by
result of past drillings

TC
Non coring
D: 76 mm
TC 6 mm×6mm

New changes:
Increaseof TC dimension: 6 mm×6mm

New ways for exist of cuttings

Step 2: Designing new bits and stabilizers by
result of past drillings

Increase
dimension of
cuttings

A Cutting act
as a base

Spiral motion
of drilling
system

Crack in wall
surface

To prevent spiral motion and lateral motion Special
stabilization was designed

These holes were considered for escape of cuttings
Adding this type of stabilization decrease lateral movement; however, these holes
do not supply enough area for escape of cuttings

……Other bits and a stabilizer were designed and
cracks that appeared in each step led to
development of final drilling system and technical
drilling….

Final Bit

Final Bit

Final Bit

Final Bit

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

How the new designed bit act?

Masonry Wall

Rod

Escape line
Of cuttings
Masonry Wall

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

Conclusion
1. Rate of penetration with non-coring bits is high. However, these bits
are not as precise as coring bits. In spite of high precision coring bits
are not so fast due to several pull out of the bits for emptying the
cores.
2. If non-coring bits are used, as the size of TCs increases, the
deviation of the hole will increase. Larger cuttings lead to asymmetric
engagement of TC and cuttings and make a permanent change in the
axis of rotation.

Conclusion
3. Stabilizers are used to increase the accuracy and decrease the
deviation in drilling path. Although, it must be noted that they
increase air pressure on the surface of the holes and crack the
finishing.
4. The most important result of this study is the combination of coring
and non-coring bits. To stabilize the drilling path and decrease the
deviation, a guide is installed on the TC-Non-Coring bit instead of
stabilizers. On the whole, this drilling bit contains a TC Coring bit
which cores from the masonry walls. This bit penetrates through the
wall as a guide and prevents the bit from deviation and out of axis
rotation. In a short distance from the TC-Coring bit, TC Non-Coring bit
is installed. This bit crushes the cores and makes the cuttings ready for
being removed from the hole as dust. The smaller the cuttings are, the
lower air pressure is needed to remove them.

Conclusion
5. This newly invented bit could use for mining, oil and other
excavations as well.
6. Hydraulic drilling machines have a better performance
compared to SGZ Rotary machine because they are larger.
7. The drilling technique must be such that the bit pressure would
be minimum.

Conclusion
8. The brick type, mortar and the quality of bricking are
determining factors for setting the drilling speed and air pressure.
It seems that we can’t have exact quantities of such factors now;
however, an expert drilling operator may achieve this.

9. During drilling operation, the speed of rotation and air pressure
could be set by observing the size of cuttings. An expert can
minimize the size of cuttings by paying attention to it.

Thanks for your kind Attention


Slide 28

Perforating the masonry walls in
rehabilitation of masonry
Buildings using center core method
Alireza Mahdizadeh - Jamaledin Borzouie

Center core method is the good suggestion for retrofitting of
Historical masonry buildings due to non-destructive
construction.

Importance of Historical Buildings
Cultural Importance
Economy of tourists

Economic Impacts

Life loss ( Historical schools)

Large cost of renovation
after earthquake

Arg-e-Bam and Bam earthquake,2003
The largest adobe building in the world
The origins of Bam : 6th to 4th centuries BC

Before Bam Earthquake,2003

After Bam Earthquake,2003

Time needed for rebuild of this structure after damage of Bam earthquake :12 years
Total cost for rebuild : 120 million $

Before Bam Earthquake,2003

After Bam Earthquake,2003

Solution

Why Center core?
others
1%

concrete
2%
steel
8%

Large number of
masonry buildings
Masonry
89%

Non-destructive method

Without Evacuation

Steps

Problems

Perforating the
masonry walls

How to perforate masonry walls
without any cracks on wall
surface

Placing bars in
holes

Area, Distance, Number of bars

Placing grout
in holes

Properties of grout

the building was studied under the critical conditions
Very weak mortar

Strong bricks

Loose finishing of the wall
Wall thickness is at most
30 centimetres
selected school: Do Shahid
The building has 3 The
stories
Aged about 50 years

Parts of Drilling systems
Drilling Machine

Rod

Hydraulic

Rotary

Drilling
Rod transmits
machinethe
produces
rotatingthe
force
energy
to the stabilizer
for rotation
and
ofbit
the bit

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer
Stabilizer reduces the lateral movements
and bit shaking along the drilling path

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer

Bits

Bit penetrates through the depth and
determines the drilling path

Principle of design
4 boreholes (total 28 m height) were perforated in this project.
In each borehole, drilling technique, equipments and bits were
changed or design according to the damage in the wall surface .
After observation of these cracks the wall surface was
destructed; moreover, a new bit or stabilizer was designed
according to movement of bit on surface of bricks and other
observations ( air pressure, rotation of bit ...) to obtain the most
suitable ones.

Step 1: changing available Bits and Stabilizers
in drilling to obtain general vision for next step
Bit properties

Diamond
Non coring
D: 76 mm
Diamond
Coring
D: 76 mm

TC
Coring
D: 93mm

picture

Damage
Bit deviation due to large
contact surface with cement

How we deal with this
new
Cracks were observed In the
part of the wall due
problem? weakest
to high air pressure and lack
of mortar in the gap between
two bricks, the air flow pushes
the finishing and damages it
such that cuttings were
dispersed.

Bit properties

TC
Non coring
D: 93 mm

picture

Damage

Cracks appear due to weak
bricking

Good Suggestion for next step
TC
Non coring
D: 66mm

Finishing remains unhurt

Step 2: Designing new bits and stabilizers by
result of past drillings

TC
Non coring
D: 76 mm
TC 6 mm×6mm

New changes:
Increaseof TC dimension: 6 mm×6mm

New ways for exist of cuttings

Step 2: Designing new bits and stabilizers by
result of past drillings

Increase
dimension of
cuttings

A Cutting act
as a base

Spiral motion
of drilling
system

Crack in wall
surface

To prevent spiral motion and lateral motion Special
stabilization was designed

These holes were considered for escape of cuttings
Adding this type of stabilization decrease lateral movement; however, these holes
do not supply enough area for escape of cuttings

……Other bits and a stabilizer were designed and
cracks that appeared in each step led to
development of final drilling system and technical
drilling….

Final Bit

Final Bit

Final Bit

Final Bit

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

How the new designed bit act?

Masonry Wall

Rod

Escape line
Of cuttings
Masonry Wall

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

Conclusion
1. Rate of penetration with non-coring bits is high. However, these bits
are not as precise as coring bits. In spite of high precision coring bits
are not so fast due to several pull out of the bits for emptying the
cores.
2. If non-coring bits are used, as the size of TCs increases, the
deviation of the hole will increase. Larger cuttings lead to asymmetric
engagement of TC and cuttings and make a permanent change in the
axis of rotation.

Conclusion
3. Stabilizers are used to increase the accuracy and decrease the
deviation in drilling path. Although, it must be noted that they
increase air pressure on the surface of the holes and crack the
finishing.
4. The most important result of this study is the combination of coring
and non-coring bits. To stabilize the drilling path and decrease the
deviation, a guide is installed on the TC-Non-Coring bit instead of
stabilizers. On the whole, this drilling bit contains a TC Coring bit
which cores from the masonry walls. This bit penetrates through the
wall as a guide and prevents the bit from deviation and out of axis
rotation. In a short distance from the TC-Coring bit, TC Non-Coring bit
is installed. This bit crushes the cores and makes the cuttings ready for
being removed from the hole as dust. The smaller the cuttings are, the
lower air pressure is needed to remove them.

Conclusion
5. This newly invented bit could use for mining, oil and other
excavations as well.
6. Hydraulic drilling machines have a better performance
compared to SGZ Rotary machine because they are larger.
7. The drilling technique must be such that the bit pressure would
be minimum.

Conclusion
8. The brick type, mortar and the quality of bricking are
determining factors for setting the drilling speed and air pressure.
It seems that we can’t have exact quantities of such factors now;
however, an expert drilling operator may achieve this.

9. During drilling operation, the speed of rotation and air pressure
could be set by observing the size of cuttings. An expert can
minimize the size of cuttings by paying attention to it.

Thanks for your kind Attention


Slide 29

Perforating the masonry walls in
rehabilitation of masonry
Buildings using center core method
Alireza Mahdizadeh - Jamaledin Borzouie

Center core method is the good suggestion for retrofitting of
Historical masonry buildings due to non-destructive
construction.

Importance of Historical Buildings
Cultural Importance
Economy of tourists

Economic Impacts

Life loss ( Historical schools)

Large cost of renovation
after earthquake

Arg-e-Bam and Bam earthquake,2003
The largest adobe building in the world
The origins of Bam : 6th to 4th centuries BC

Before Bam Earthquake,2003

After Bam Earthquake,2003

Time needed for rebuild of this structure after damage of Bam earthquake :12 years
Total cost for rebuild : 120 million $

Before Bam Earthquake,2003

After Bam Earthquake,2003

Solution

Why Center core?
others
1%

concrete
2%
steel
8%

Large number of
masonry buildings
Masonry
89%

Non-destructive method

Without Evacuation

Steps

Problems

Perforating the
masonry walls

How to perforate masonry walls
without any cracks on wall
surface

Placing bars in
holes

Area, Distance, Number of bars

Placing grout
in holes

Properties of grout

the building was studied under the critical conditions
Very weak mortar

Strong bricks

Loose finishing of the wall
Wall thickness is at most
30 centimetres
selected school: Do Shahid
The building has 3 The
stories
Aged about 50 years

Parts of Drilling systems
Drilling Machine

Rod

Hydraulic

Rotary

Drilling
Rod transmits
machinethe
produces
rotatingthe
force
energy
to the stabilizer
for rotation
and
ofbit
the bit

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer
Stabilizer reduces the lateral movements
and bit shaking along the drilling path

Parts of Drilling systems
Drilling Machine

Rod

Stabilizer

Bits

Bit penetrates through the depth and
determines the drilling path

Principle of design
4 boreholes (total 28 m height) were perforated in this project.
In each borehole, drilling technique, equipments and bits were
changed or design according to the damage in the wall surface .
After observation of these cracks the wall surface was
destructed; moreover, a new bit or stabilizer was designed
according to movement of bit on surface of bricks and other
observations ( air pressure, rotation of bit ...) to obtain the most
suitable ones.

Step 1: changing available Bits and Stabilizers
in drilling to obtain general vision for next step
Bit properties

Diamond
Non coring
D: 76 mm
Diamond
Coring
D: 76 mm

TC
Coring
D: 93mm

picture

Damage
Bit deviation due to large
contact surface with cement

How we deal with this
new
Cracks were observed In the
part of the wall due
problem? weakest
to high air pressure and lack
of mortar in the gap between
two bricks, the air flow pushes
the finishing and damages it
such that cuttings were
dispersed.

Bit properties

TC
Non coring
D: 93 mm

picture

Damage

Cracks appear due to weak
bricking

Good Suggestion for next step
TC
Non coring
D: 66mm

Finishing remains unhurt

Step 2: Designing new bits and stabilizers by
result of past drillings

TC
Non coring
D: 76 mm
TC 6 mm×6mm

New changes:
Increaseof TC dimension: 6 mm×6mm

New ways for exist of cuttings

Step 2: Designing new bits and stabilizers by
result of past drillings

Increase
dimension of
cuttings

A Cutting act
as a base

Spiral motion
of drilling
system

Crack in wall
surface

To prevent spiral motion and lateral motion Special
stabilization was designed

These holes were considered for escape of cuttings
Adding this type of stabilization decrease lateral movement; however, these holes
do not supply enough area for escape of cuttings

……Other bits and a stabilizer were designed and
cracks that appeared in each step led to
development of final drilling system and technical
drilling….

Final Bit

Final Bit

Final Bit

Final Bit

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

How the new designed bit act?

Masonry Wall

Rod

Escape line
Of cuttings
Masonry Wall

Non-Coring part
Main Drilling part
Coring part of bit
guide the bit way

Conclusion
1. Rate of penetration with non-coring bits is high. However, these bits
are not as precise as coring bits. In spite of high precision coring bits
are not so fast due to several pull out of the bits for emptying the
cores.
2. If non-coring bits are used, as the size of TCs increases, the
deviation of the hole will increase. Larger cuttings lead to asymmetric
engagement of TC and cuttings and make a permanent change in the
axis of rotation.

Conclusion
3. Stabilizers are used to increase the accuracy and decrease the
deviation in drilling path. Although, it must be noted that they
increase air pressure on the surface of the holes and crack the
finishing.
4. The most important result of this study is the combination of coring
and non-coring bits. To stabilize the drilling path and decrease the
deviation, a guide is installed on the TC-Non-Coring bit instead of
stabilizers. On the whole, this drilling bit contains a TC Coring bit
which cores from the masonry walls. This bit penetrates through the
wall as a guide and prevents the bit from deviation and out of axis
rotation. In a short distance from the TC-Coring bit, TC Non-Coring bit
is installed. This bit crushes the cores and makes the cuttings ready for
being removed from the hole as dust. The smaller the cuttings are, the
lower air pressure is needed to remove them.

Conclusion
5. This newly invented bit could use for mining, oil and other
excavations as well.
6. Hydraulic drilling machines have a better performance
compared to SGZ Rotary machine because they are larger.
7. The drilling technique must be such that the bit pressure would
be minimum.

Conclusion
8. The brick type, mortar and the quality of bricking are
determining factors for setting the drilling speed and air pressure.
It seems that we can’t have exact quantities of such factors now;
however, an expert drilling operator may achieve this.

9. During drilling operation, the speed of rotation and air pressure
could be set by observing the size of cuttings. An expert can
minimize the size of cuttings by paying attention to it.

Thanks for your kind Attention