Soil Conditioning Basics - Tunneling Short Course · Benefits of Soil Conditioning in EPBM. 8. EPB...
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Soil Conditioning Basics in Pressurized Face TBMs Jim Lindsay BASF Region Head UGC-NAFTA
Transcript of Soil Conditioning Basics - Tunneling Short Course · Benefits of Soil Conditioning in EPBM. 8. EPB...
Soil Conditioning Basicsin Pressurized Face TBMs
Jim LindsayBASF Region Head UGC-NAFTA
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3 Main Types of TBMs
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EPB for SOFT GROUND AND COHESIVE SOILS
MIXSHIELDS for HETEROGENEOUS GROUNDS / HIGH WATER PRESSURES
HARD ROCK TBMS for MINING IN ROCK AND NON GROUND WATER BEARING SOILS
EPB SEATTLESR-99 MIXSHIELD CHINA HARD ROCK TUNEL LA CABRERA SPAIN
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EPB Shield- Operation Related to Conditioning
• Cutterhead
• Working Chamber
• Screw Conveyor
• TBM Shield
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EPB Shield- Operation Related to Conditioning
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Actual range of EPB use- Soils and Conditioning Considerations
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Actual range of EPB use- Soils and Conditioning Considerations
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Benefits of Soil Conditioning in EPBM
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EPB Shield Foam / Polymer Varietals
Different foams have different properties Foaming capacity Stability Anti-clay capacity Rheological impact (liquefaction /
stiffening) Drying-up capacity
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Soil RheologySoil Conditioning Agent- General Concept
A Carrier ‘or’ Vehicle of soils
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0
20,000
40,000
60,000
80,000
100,000
120,000
0.001 0.01 0.1
Torq
ue, [
µNm
]
Shear rate, [1/s]
Rheometry data, Torque
Control at LL "321" FER 15 FIR 100 ACP 147+ FER 15 FIR 100
Soil Conditioning Agents- Torque Reduction
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Anti-Clay Polymer
Static and Steric Repulsion
Reduction of particle adhesion
Flocculation
Purpose
Decrease clogging, adhesion, transport problems
Reduction in Torque
Increase the TBM speed
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Soil Conditioning Agents- Anti-Clay Foams/Polymers
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0
100,000
200,000
300,000
400,000
500,000
600,000
700,000
800,000
0.001 0.01 0.1
Visc
osity
, [Pa
·s]
Shear Rate, [1/s]
Rheometry data, Viscosity
Control at LL "321" FER 15 FIR 100 ACP 147+ FER 15 FIR 100
Soil Conditioning Agents- Soil Viscosity
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Soil Conditioning Agents- Specialty Polymers
Polymers
Adhesive Polymers
Super Water Absorbers
Water Management
Purpose
Increase Soil Adhesion
Stabilize Soil Matrix
Decrease Water Inflow
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EPBM- FOAM GENERATION Basics
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Foaming solutionWater
Additive
AirFoaming solution
Surfactant Polymer Additive
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Super Absorbers
Anti-washout Polymers
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Soil Conditioning Agents- Specialties
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MasterRoc SWA 705
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Soil Conditioning AgentsMasterRoc® Polymers
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Conclusions
Soil Conditioners for all needs
Gravel to Clayey soils
Foam Generation, Expansion and Injection Rates play important roles
Consider Foam Behavior under Pressure
Transportability, Torque Reduction and Advance rate are affected
Foam Stability is Key
020406080
100120140160
-200 300 800 1300 1800
Hei
ght,
mm
Time, sec
Foam Height (mm)
