Transcript Earth Retaining System

Hashemite University
Department of Civil Engineering
Foundation Engineering
Dr. Omar Al-Hattamleh
Earth Retaining System
Earth slopes and earth retaining structures
Used to maintain two different ground surface elevations
Types of Earth Retaining Structure
Rigid Gravity and semi gravity Walls
•CIP Concrete Gravity Wall
•CIP concrete cantilever Wall
•Prefabricated Modular Gravity Wall
•Crib Wall
•Bin Wall
•Gabion Wall
Non Gravity Cantilevered Walls
•Sheet pile Wall
•Soldier pile and logging Wall
•Slurry Wall
•Tangent And Secant Wall
•SMW Wall
•Anchored Wall
MSE WALLS
•Segmented Pre-cast facing Sys.
•Prefabricated Modular Block MSE
•Geotextile, Geogrid MSE wall
•Reinforced Soil Slope
In Situ Reinforced Wall
•Soil Nail
•Micro-pile
Cut Wall Construction
Internally Stabilized
Externally Stabilized
Fill Wall Construction
A cantilever gravity wall.
CIP (Cast in Place)
Concrete
Cantilever Wall
CIP (Cast in Place)
Concrete Cantilever Wall
 Description
Cast in place concrete cantilever/ counter forth wall consist of a steel
reinforced concrete wall stem and base slab connected to for the
shape of an inverted T.
 General
1. Typical Application: Bridge abutments, retaining walls, soil stabilization
2. Size requirements: Base width of ranges from 0.4 to 0.7 of the wall height
3. Typical Height Range: 2-9 m Cantilever wall; 9-18 m (counter forth Wall)
 Advantages
1. Conventional Wall System with Well established design procedure &
performance characteristics
2. Concrete is very durable in many environments
3. Concrete can be formed, textured, and colored to meet aesthetic
requirements
CIP Concrete Cantilever Wall Cont.

Disadvantages
1.
Requires relatively long construction period: formwork must be
erected & concrete poured and allowed to cure before backfill
loads
2.
3.
Costly :
a) Required selected backfill if not available near the site
b) May need temporary excavation support
c) Deep foundation support
Wall system is rigid and its sensitive to total and differential
settlements
Gabion Wall
 Description
Compartment unit filled with stone that is 100 to 200 mm in size. Each
unit is a rectangular basket made of galvanized steel, geosynthetic grid or
polyvinylchloride (PVC) coated wire. Each gabion units laced together on
site and filled with selected stone
 General
1. Typical Application: Retaining walls, Slope stabilization, bank stabilization
2. Size requirements: Base width of ranges from 0.5 to 0.7 of the wall height
3. Typical Height Range: 2-8m
 Advantages
1. Wall System is flexible and can accommodate large and differential
settlements with out distress
2. Wall appearance well suited to rural areas
3. Wall flexible, therefore, suited for application in high seismicity area
4. Wall pervious, therefore, well suited foe bank stabilization applications
Gabion Wall Cont.

Disadvantages
1.
2.
3.
Source of stone must be available
Gabion wire are subjected to corrosion in aggressive soils
Abrasion of the gabion baskets may occur in water way
application
Requires significant manual labor
Not cost effective for temporary applications
4.
5.
Sheet Pile Wall
Sheet Pile Wall
Sheet Pile Wall
 Description
Consist of driven, vibrated, or pushed, interlocking steel or concrete sheet
pile sections. The required depth of embedment (i.e. length of sheet pile
below final excavated grade) is evaluated based on the assumption that
the passive resistance of the soil in front of the wall plus flexural strength
of the sheet pile can resist the lateral forces from the soil behind the wall
 General
1. Typical Application: Retaining walls, Slope stabilization, excavation support
Marine walls, docks
2. Size requirements: N/A
3. Typical Height Range: 2-5m
 Advantages
1. Conventional Wall System with Well established design procedure &
performance characteristics
2. Wall system can be used for application in which wall can penetrates
below ground water table
3. Work area inside wall face is not required
4. Wall system is suitable for temporary applications
Sheet Pile Wall Cont.

Disadvantages
1.
Requires specialized equipment
2.
Driven sheet pile is noisy and it can be introduce vibration
3.
Difficult to drive sheet in hard or dense or gravelly soil
4.
Wall height is limited based on required structural sections
5.
Wall system may undergo relatively movements which may be
detrimental to nearby structure
SMW Wall (Soil Mixed Wall)
 Description
Consist of overlapped soil-cement columns in which in situ soils are mixed
with a cement slurry or other hardening agent. A multiple axis auger and
mixing paddles are used to construct overlapping soil cement columns
without soil removal or unmixed zones between columns.
 General
1. Typical Application: Retaining walls, excavation support
2. Size requirements: typically 1.0 m
3. Typical Height Range: 6-24 m with anchors
 Advantages
1. Reduce excavated spoil is produced
2. Is adaptable to an irregular installation arrangement
SMW Wall (Soil Mixed Wall) Cont.

Disadvantages
1.
Design procedures are not well established
2.
Construction of wall system requires specialty contractor and
equipment vibration
3.
Quality control/ quality assurance protocol is not well documented
for this wall system
4.
Disposal of excavated spoil resulting from soil mixing process
may be costly do to environmental restrictions
Soil Nailed Wall
Soil Nailed Wall
 Description
In Situ soil reinforcement technique wherein passive inclusions (soil nails)
are placed into the natural ground at relatively close spacing (1-2 m) to
increase the strength of the soil mass. Construction staged from top to
down and after each stage of excavation, the nails are installed, drainage
system are constructed and shotcrete are applied to the excavation face.
 General
1. Typical Application: Retaining walls, soil stabilization, excavation support
2. Size requirements: soil nail length typically from 0.6- 1.0 m of the wall height
3. Typical Height Range: 3-20 m
 Advantages
1. An unobstructed working space can be achieved on the excavation side of
the wall
2. Surface movements can be limited by installing additional nails or by
stressing nails in upper level to small percentage of working loads
3. Wall system is adaptable to varying site conditions
4. Is well suited for construction in areas of limited head room
5. Wall embedment is nor required
6. Suitable for temporary applications
SMW Wall (Soil Mixed Wall) Cont.

Disadvantages
1.
Construction of wall system requires specialty contractor
2.
Required permanently dewatering in case of the present of
ground table
3.
Closed space nail May interface underground utilities
4.
Nail capacity may be difficult to develop in some cohesive soil
Segmental, Precast Facing
Mechanically Stabilized Earth Walls
Segmental, Precast Facing
Mechanically Stabilized Earth Walls
Segmental, Precast Facing
Mechanically Stabilized Earth Walls
 Description
A segmental, pre-cast facing mechanically stabilized earth wall employs
metallic (strip or bar mat) or geosynthetic (geogrid or geotextile)
reinforcement that is connected to a precast concrete or prefabricated
metal facing a panel to create a reinforced soil mass. Facing Panel are
typically square, rectangular, hexagonal or cruciform in shape
 General
1. Typical Application: Bridge abutments, retaining wall, slope stabilization
2. Size requirements: minimum reinforcement length of 0.7 m of the wall height
3. Typical Height Range: 3-20 m
 Advantages
1.
2.
3.
4.
5.
6.
Rapid construction; does not required specialized labor
Limited foundation preparation
Flexible; accommodate large differential settlement
Reinforcement is light and easily to handle
Flexibility in choice facing and architectural finishes
Suitable for regions in high seismicity
Segmental, Precast Facing
Mechanically Stabilized Earth Walls Cont.

1.
Disadvantages
Not economical for cut application due to additional cost in
temporary excavation
Requires relatively large base width
Use of metallic reinfrorcment requires a minimum electrochemical
requirements for corrosions
Allowable loads for geosynthetic reinforcement must be reduced
to account for creep, durability, and construction damage
Not appropriate for
2.
3.
4.
5.



6.
If we need access to underground utilities
Locations subjected to scour
Place involving significant horizontal curvature
Not cost effective for temporary applications
RSS Reinforced Soil Slope
Description
These systems incorporating planner reinforcement, typically geotextile or
geogrid in construct the earth slope face inclination less than 70o. The
reinforcement is laid down alternately with horizontal layers of compacted
soil.
 General
1. Typical Application: Slope stabilization, embankment construction
Sound/ Noise absorbing embankment wall
2. Size requirements: min. reinforcement length of 0.5-1.0m of the wall height
3. Typical Height Range: 3-30 m
 Advantages
1.
2.
3.
4.
5.
6.
7.
8.
Rapid construction; does not required specialized labor
Limited foundation preparation
Flexible; accommodate large differential & total settlement
Reinforcement is light and easily to handle
Extremely Flexible suited for seismic zones
Suitable for regions in high seismicity
Vegetation of the slope possible
Can be used for construction of very height embankment over 30m
RSS Reinforced Soil Slope Cont.

Disadvantages
1.
Non vertical slope increase right of way compared to a vertical
wall
2.
Requires relatively large base width
3.
Geotextile and geogrid requires relatively large base width
4.
Geotextile and geogrid life is reduced due to exposure to
ultraviolet light
Crib Wall
http://www.concrib.com.au/gallery_cribwall.htm
Crib Wall
Crib Wall
Crib Wall
Segmental Retaining Wall
Gabion
Gabion
Bin Wall
http://www.contech-cpi.com/default.aspx
CONSTRUCTION OF
SECANT PILE WALL
http://www.lta.gov.sg/projects/images/Secant%20Final.pdf
CONSTRUCTION OF
SECANT PILE WALL