Detlef Jordan - The Robbins Company

PROVEN CONCEPTS

DIFFICULT GROUND

SOLUTIONS (DGS)

DETLEF JORDAN, SALES MANAGER EUROPE,

THE ROBBINS COMPANY

14th Australian Tunneling Conference & Exhibition, Sydney, Australia

11 – 12 October 2016

• Reduces risk to Contractors and Owners when

a challenge is encountered:

• Squeezing ground

• Fault zones

• Water inflows

• Mixed face conditions

• Blocky rock

INTRODUCTION

DIFFICULT GROUND SOLUTIONS

BENEFITS

KEY FEATURES

DGS

FACT: Geological predictions are conjecture at

best.

TBM FEATURES FOR DIFFICULT GROUND

STRATEGY

• Good geological advance

investigation within the tunnel is

cost effective

• Probe drilling in advance of face

• Multiple probe holes in faulted areas

Probe drilling in advance of face

GOOD GROUND KNOWLEDGE

DETECTION

CASE STUDY: RONDOUT WEST BYPASS

PROBE DRILLING

360-degree probe drilling capabilities

Water-powered down-the-hole hammers

Capable of accurate drilling at long distances: 60 to 100 m ahead of the TBM

TBM FEATURES FOR DIFFICULT GROUND

STRATEGY

MEASUREMENT WHILE DRILLING (MWD) &

OTHER SYSTEMS

• MWD system and TBM data interprets geological model

• Understanding the rock mass, improving general performance

• Documentation of the existing rock formation

• Amberg TSP System

• One or more shot lines w/small explosive charges

• Four receivers

• Geoelectrical BEAM System

• Whole cutterhead or single cutting tools can act as measuring electrode

WATER

TBMs FOR

DIFFICULT

GROUND

CASE STUDY: RONDOUT WEST BYPASS

TUNNELING IN ROCK WITH WATER

WATER INFLOW PREVENTION

Three-axis main bearing

with 35 bar static pressure

protection by multiple lip

seal arrangement with

emergency seal feature

Outer Seal Layout

Inner Seal Layout

CASE STUDY: RONDOUT WEST BYPASS

MUCK CHUTE CLOSURE DOORS

• Closing the muck chute during water inflow

• Purpose is to reduce the volume of incoming water through the muck chute

• Stop Fines from flooding into tunnel

TUNNELING IN ROCK WITH WATER

FACE COLLAPSE

TBMs FOR

DIFFICULT

GROUND

TBM FEATURES FOR DIFFICULT GROUND

FACE COLLAPSE

• Temposonic cylinder to measure distance from shield to ground

• Cameras to inspect and understand ground stability in the face

COLLAPSE DETECTION CYLINDER &

FACE INSPECTION CAMERAS

CAMERA PORTS

CASE STUDY: RONDOUT WEST BYPASS

FACE COLLAPSE

Two speed gearboxes allow both,

high torque and high speed without

increasing HP/KW

Low RPM/High Torque

High RPM/Low Torque

0

2000

4000

6000

8000

10000

12000

14000

0 2 4 6 8 10

Cu

tte

rhea

d T

orq

ue

(kN

m)

Cutterhead Speed (RPM)

Gerede Torque CurveTwo-Speed Gearbox

Low Speed

Exceptional LowSpeed

High Speed

Exceptional HighSpeed

HIGH-TORQUE MAIN DRIVESWhen loose material comes against the cutter head higher torque is required

to commence rotation

SQUEEZING GROUND

TBMs FOR

DIFFICULT

GROUND

TBM FEATURES FOR DIFFICULT GROUND

CHEMICAL GROUTWands pushed into face and chemical additive (Polyurethane) is

pumped into the wands to consolidate the face

STRATEGY

TBM FEATURES FOR DIFFICULT GROUND

STRATEGY

Typical overlapping forepoling arrangement

FOREPOLING

RAPID ADVANCE SHIELDS

Features to effectively excavate

in squeezing conditions:

• Shorter shield design

• Stepped/tapered shields

• Peripheral shield lubrication

• Hydraulic shield breakout

facility

STRATEGY

TBM FEATURES FOR DIFFICULT GROUND

RAPID ADVANCE SHIELDS

• Stepped shield design

• Peripheral shield lubrication

View of stepped shields (left)

and peripheral shield lubrication

port (above)

STRATEGY

CASE STUDY: RONDOUT WEST BYPASS

TBM FEATURES FOR DIFFICULT GROUND

STRATEGY

• When needed additional thrust force can be generated to move the TBM in

difficult ground

• Additional hydraulic rams are used to increase the total available machine

thrust to break the TBM free

HIGH PRESSURE JACK

SUPER THRUST

CONCLUSIONS

CONCLUSIONS

TBMs IN DIFFICULT GROUND

• The features of Difficult Ground

Solutions (DGS) provide accurate

ground investigation, particularly on

shielded TBMs

• DGS is well-suited to long tunnels and

tunnels in hard rock or mixed ground

• DGS features should be built into the

TBM in case of adverse conditions

• The efficacy of DGS is there to assist

when it is obvious, a meter-by-meter

geological report cannot be

economically provided

THANK YOU !