Transcript Rock Bolting for 21st Century

Self Drilling Rock Bolt
System
for the Coal Industry
Ground Support Services Pty Ltd & Alminco Pty Ltd
March 2008
Advanced SDRB System

Installation System

New Alminco Crawler Rig

Integrated Bolting & Resin Pumping System

Standard Steel SDRB

New Telescopic SDRB

New Fibreglass SDRB

Future Directions
© 2008 GSS Pty Ltd & Alminco Pty Ltd
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Objectives of the SDRB project:
 Pumpable Resin Bolting System
 Fit existing machines

Resin tanks, resin pumps, delivery system etc
 Roof and Rib support
 Minimise manual handling
 Maximise rock support
 Improve Productivity
© 2008 GSS Pty Ltd & Alminco Pty Ltd
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Installation System
Standard Crawler Rig with new
engineering features:
 Integrated & self contained
 Operator seated remote from
drilling & resin injection
operation
 Standard drill mast – vertical
& horizontal drilling
 New innovative Drilling
Chuck
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Installation System
New Drilling Chuck features:
 lightweight with RH & LH mounting
 offset drive motor with quick detach
injection head
 2 speed with RH & LH rotation
 through drive socket tension to roof
© 2008 GSS Pty Ltd & Alminco Pty Ltd
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Resin System
Resin Delivery System:
 Two separate systems with
resin pressure control
 Twin 120 litre tanks (easily
increased)
 New Injection Head:
 seamless water & resin
injection & flushing
 quick change over &
replacement
© 2008 GSS Pty Ltd & Alminco Pty Ltd
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Why Pumpable Resin SDRB?

Full bolt encapsulation maximises roof support

Resin fills cracks & cavities

No gloving, no plastic film

Perfect resin mixing every time

Resin fills bearing plate & locks mesh in place

Minimises water inflow & bolt corrosion
full encapsulation both inside and outside bolt
resin fills bearing plate & also locks mesh in place
visible resin at collar proves full encapsulation
© 2008 GSS Pty Ltd & Alminco Pty Ltd
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Plate Design

Round design – stackable with no orientation required

“soft” footprint won’t damage mesh

Large plate “footprint”

Resin can fill bearing plate & lock mesh in place & provide intimate
surface contact

Once full of resin, becomes very strong in compression
© 2008 GSS Pty Ltd & Alminco Pty Ltd
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Standard Steel SDRB
 One piece
 No drive dollies, no drill rods, no resin cartridges
 fast penetration with high thrust
 High Capacity ~ 36 tonnes
 High load transfer capacity >1.4 tonnes/cm
 Custom bearing plates with “soft” footprint
© 2008 GSS Pty Ltd & Alminco Pty Ltd
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Rock Drilling
Rock Drilling with SDRBs:
 Possible to drill 80 MPa concrete with blue metal
 Tungsten carbide ensures maximum penetration rate
 Tungsten carbide equates to about 4 seconds in time cost
© 2008 GSS Pty Ltd & Alminco Pty Ltd
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Principle of the Telescopic SDRB
1
2
3
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Principle of the Telescopic SDRB
~3.4m
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New Telescopic SDRB
 One piece
 Automatically extendable
 No couplers, no drive dollies, no
drill rods, no resin cartridges
 High Capacity ~ 36 tonnes
 High load transfer capacity ~2.0
tonnes/cm
1.9m
3.4m
 Fast, simple
© 2008 GSS Pty Ltd & Alminco Pty Ltd
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New Fibreglass SDRB
Fits same Drill Chuck as steel SDRBs
nut & thread >10 tonnes
Hollow Fibreglass Rod >30 tonnes
Simple, high speed, high capacity
© 2008 GSS Pty Ltd & Alminco Pty Ltd
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New Fibreglass SDRB
Spiral wound surface provides undulations
Grit coated surface
Surface provides very high load transfer capacity ~ 1 tonne/cm
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New Fibreglass SDRB
Injection moulded thread
Hollow Fibreglass Rod
Hardened Steel Drill Bit
Small borehole annulus
© 2008 GSS Pty Ltd & Alminco Pty Ltd
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New Fibreglass SDRB
Coal Drilling in Ribs:
 hardened steel drill bits okay for
coal ribs
 patented Drill Bit design enables
small borehole annulus
 minimises resin volume
 maximises load transfer
capacity
© 2008 GSS Pty Ltd & Alminco Pty Ltd
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Bolt Performance
Fibreglass
Telescopic
Steel SDRB
X Grade
0.0
0.5
1.0
1.5
2.0
2.5
Load Transfer Capacity (tonnes per cm)
Fibreglass
Telescopic
Steel SDRB
X Grade
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
Ultimate Tensile Strength (tonnes)
© 2008 GSS Pty Ltd & Alminco Pty Ltd
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SDRB Drilling in 80 MPa concrete
Points to Note:

Drilling in 80 MPa concrete with blue metal

Penetration rate reasonable

Rotary drilling only – no percussive

Note water being displaced by resin

Full resin encapsulation of bolt and plate
© 2008 GSS Pty Ltd & Alminco Pty Ltd
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Full Resin Encapsulation
Resin filling “cavities”
The pumpable resin system synergistically
enhances the SDRB & the bearing plate
© 2008 GSS Pty Ltd & Alminco Pty Ltd
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Future Directions:

Refine & test Crawler mounted System

Large scale secondary bolting demonstration

Quantify field support performance:

mechanical & geotechnical & cycle times

Engineering design for a production face system

Future Continuous Miner mounted system
© 2008 GSS Pty Ltd & Alminco Pty Ltd
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Thanks:
Acarp
Xstrata
Alminco
© 2008 GSS Pty Ltd & Alminco Pty Ltd
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