Adam Foulstone - Anglo America - The Grosvenor TBM Mine project

GROSVENOR PROJECTDEVELOPMENT OF COAL MINE DRIFTS UTILISING A TUNNEL BORING MACHINE

OVERVIEW

•Site project description

•TBM Specifications

•Methodology

•Drift construction

•Advantages & achievements

•Conclusions

SITE AND PROJECT DESCRIPTION

•Project overview

•Geology

•QLD Mine Regulations

•Options Considered

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SITE AND PROJECT DESCRIPTIONProject overview

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SITE AND PROJECT DESCRIPTIONProject overview

Longwall Panels- 300m Wide- 6200m Long

Man & Materials Drift- 1:8 Decline- 1,100m Long

Conveyor Drift- 1:6 Decline- 900m Long

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SITE AND PROJECT DESCRIPTIONGeology Overview – Conveyor Drift

Chainage Description Classification

0 – 118 Box Cut -

118 – 220 Cainozoic Sediments Soft Ground

220 – 230 Tertiary - Weathered Basalt Soft Ground

230 – 300 Tertiary Sediments Soft Ground

300 – 880 Permian – Siltstone / Sandstone Hard Ground

880 – 914 GM Seam Coal Soft Ground

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SITE AND PROJECT DESCRIPTIONGeology Overview – Man and Material Drift

Chainage Description Classification

0 – 142 Box Cut -

142 – 180 Cainozoic Sediments Soft Ground

180 – 250 Tertiary - Weathered Basalt Soft Ground

250 – 350 Tertiary Sediments Soft Ground

350 – 580 Permian – Siltstone / Sandstone Hard Ground

580 – 700 Permian – P Seam Coal Soft Ground

700 – 1050 Permian Siltstone / Sandstone Hard Ground

1050 – 1154 GM Seam Coal Soft Ground

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SITE AND PROJECT DESCRIPTION

QLD Mine Regulations

• TBM’s have been sporadically used within Coal Mining:

• TBM proposal new to QLD Coal Mining

• Risk Assessment to determine ERZ1/NERZ

• NERZ = CH4 < 0.5%

• ERZ1 = 0.5% < CH4 < 2.0%

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SITE AND PROJECT DESCRIPTIONOptions Considered

• Summary of project conditions

• Variable/mixed ground conditions

• Project schedule

• Cost implications

• QLD Coal Mining Legislation

• Options Considered

• Drill and Blast techniques

• Conventional road header

• Earth Pressure Balance Machine

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SITE AND PROJECT DESCRIPTIONOptions Considered

Options Considered• Excavation Rate• Cutting Profile / Accuracy• Tunnel design parameters• Ground support• Work Environment• Capital cost• Operating cost

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SITE AND PROJECT DESCRIPTIONOptions Considered

Options Considered• Excavation Rate• Cutting Profile / Accuracy• Tunnel design parameters• Ground support• Work Environment• Capital cost• Operating cost

In comparison to conventional drill and blast operations or roadheader the TBM was more favorable.

TBM SPECIFICATIONS

•EPBM (dual mode)

•Gas Compliance

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TBM SPECIFICATIONSEPBM (dual mode)

TBM Design Criteria:

• Purpose built TBM to cope with Grosvenor specific

conditions

• Compliant with QLD Coal Mining Regulations

• Capability to complete multiple drifts (no exit point)

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TBM SPECIFICATIONSEPBM (dual mode)

Drift Layout:

• Vertical Curve – 400m radius

• Segmental lining ID 7.0m

• Consists of steel-fiber reinforced lining (universal

ring 5 + 1 key segments)

• Additional flat segment placed at invert level to

allow transit along the tunnel

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TBM SPECIFICATIONSEPBM (dual mode)

TBM Specifications – Robbins Hybrid / Dual Mode

Bore Diameter (m) 8 Cutterhead Mixed ground / convertible

Total Length (m) 135 Cutters 17” disc / Knife Edge

TBM Weight (t) 994 Cutterhead Power (kW) 12 x 330 kW (3,960 kW)

UCS (MPa) 100 (Max) Cutterhead Speed (RPM) 0 – 6.4

Hydrostatic Pressure (Bar) 3 Maximum Thrust (kN) 22,619

Screw Conveyor Double, shafted Number of Segments 5 + 1 key + invert

Methane Monitors 6 x locations Segment Width (m) 1.4

Explosion-Proof EPB Sensors 10 x locations Segment Thickness (m) 0.35

Segment Backfill Bi-component grout

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TBM SPECIFICATIONSEPBM (dual mode)

Cutterhead Details:

• EPB:

• Rock mode:

EPB Mode – Bi-directional Rock Mode – Single direction Mixed Ground Mode – Bi-directional

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TBM SPECIFICATIONSEPBM (dual mode)

Double Screw Conveyor:

Forward Shield:

• Inner shield - Removed

• Outer Shield – Remain insitu

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TBM SPECIFICATIONSGas Compliance

Sources of Gas:

• Expected: Methane release from carbonaceous

inclusions

• Unexpected: Hydrocarbons released from greases

and foams

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TBM SPECIFICATIONSGas Compliance

Principal Method of Gas Control:

• Pre-cast concrete linings

• Fully grouted into place as shield advances, sealing

from ingress of water or gas

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TBM SPECIFICATIONSGas Compliance

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TBM SPECIFICATIONSGas Compliance

METHODOLOGY

•Box Cut

•EPBM Assembly OFTA

•Conveyor Drift

•Retrieval / Relocation

•Man & Materials Drift

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METHODOLOGYBox Cut

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METHODOLOGYBox Cut

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METHODOLOGYEPBM Assembly OFTA

Onsite First Time Assembly (OFTA):

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METHODOLOGYConveyor Drift

Conveyor Drift Performance

Total Length (m) 798 Average Rings / Day 3.8

Total Rings (number) 578 Maximum Rings / Day 13

Duration (days) 153Average Production

(m/week)40

TBM Mode (%)100% - Mixed Ground

Configuration

Average TBM Availability

(%)67

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METHODOLOGYRetrieval / Relocation

Retrieval Requirements:

• TBM to be used in multiple drifts

• TBM to disassembled

• TBM to be retracted

Design Features:

• Cutterhead inner and outer

• Forward and rear shields

• Cutterhead core

• Self-propelled walking dolly system

• Back-up gantries fitted with jacks to provide anti-slide

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METHODOLOGYRetrieval / Relocation

Retrieval Requirements:

• TBM to

CH

Segments

CH core

Inner Shield

Outer

Shield

CHS

CHS Dolly

Front Dolly Bridge

Dolly

Sliding

Track

Segment

ErectorBridgeScrew Conveyor

5.8m

Lift Jacks

Inner Shield

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METHODOLOGYRetrieval / Relocation

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METHODOLOGYRetrieval / Relocation

Front Dolly Frame on Surface Launching Slab

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METHODOLOGYCommence inseam coal Mining Operations

Free face available to commence Development Operations

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METHODOLOGYRetrieval / Relocation

SPMT For Transport to the Man and Materials Drift

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METHODOLOGYRetrieval / Relocation

SPMT For Transport to the Man and Materials Drift

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METHODOLOGYMan & Materials Drift

Man & Materials Drift Performance

Total Length (m) 988 Average Rings / Day 7.7

Total Rings (number) 732 Maximum Rings / Day 18

Duration (days) 95Average Production

(m/week)70

TBM Mode (%)63% - Scrapper / Knife bits

37% - Full cutter disc

Average TBM Availability

(%)78

DRIFT CONSTRUCTION

•Modifications through “Lessons Learnt”

Conveyor drift

•Performance Comparison – Conveyor Drift vs..

Man & Materials Drift

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DRIFT CONSTRUCTIONModifications

Modifications:

• Operational

• Mechanical

• Foam System – redesign to increase capacity

• Cutter Head Configuration – modifications to grizzly

bar / mixing paddle

• Grouting – revised design for mixing chambers and

auto flushing

• Conveyor System – revise design to improve

efficiencies

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DRIFT CONSTRUCTIONPerformance Comparison

Conveyor Drift Man & Materials Drift

Total Length (m) 798 988

Total Rings (number) 578 732

Duration (days) 153 95

Rings / Day (Average and Max) 3.8 (13) 7.7 (18)

Average (m/week) 40 70

TBM Availability (%) 67 78

ADVANTAGES & ACHIEVEMENTS

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ADVANTAGES

Advantages:

• Improved working conditions

• Increased penetration rates

• Durable concrete lining constructed during boring

process

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ACHIEVEMENTThe End Product

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TBM Breakthrough – Man & Materials Drift

CONCLUSIONS