Tunnelling and Support Design

TBM (tunnel boring machine) is the machine which use for the excavation of tunnel, galery , underground openings in metro, water, energy construction and mining projects etc. Advantages of EPB Lower capital cost Smaller site and launch Muck is immediately ready for disposal In case of face collapse amount of ground loss is limited

MAD 427

Tunnelling and Support Design

Lecturer: Prof Dr.Bahtiyar ÜNVER

Subject: EPB and SLURRY types TBM

Janurary 2012

WHAT IS THE TBM?

WHAT IS THE TBM?

TBM (tunnel boring machine) is the

machine which use for the excavation of

tunnel, galery, underground openings in metro, water, energy construction and

mining projects etc

TYPES OF TBM

TBM

Soft Rock

Hard Rock

Gripper

EPB (Earth PressureBalance)

Type TBM

Working Area Condition EPB

 Silt and clay (fine grained size)

 Max 4 bar pressure (if over pressure

we can not use)

 We do not want more water

Advantages of EPB

 Lower capital cost

 Smaller site and launch

 Muck is immediately ready for disposal

 In case of face collapse amount of

ground loss is limited

Disadvantages of EPB

 Requires higher torque

 Requires greater Cuttinghead power

 Required confinement pressure must

be calculated

 Muck is exposed into tunnel

Slurry type TBM

Working Area Conditions

Slurry

 Sand and gravel

 If we got more water income (slurry condition )

 We can use approxiametly more than

10 bar pressure ( i.e In Bosphorus 13 bar pressure)

Advantages of Slurry

 Lower torque

 Lower Cuttinghead Power

 Cleaner Tunnel Environment

 Contaminated muck is not exposed until it reaches the surface

Disadvantages of Slurry

 Requires a large size job site

 Higher capital costs

 Higher power requirement

 Requires extensive addition of material

MAD 427

Tunnelling and Support Design

Applications in TURKEY

Collapse

If the ground pressure higher than the machine pressure The result ;

Swelling

If the ground pressure lower than the machine pressure The result ;

Leakage of Additivies

If we don’t control the additives and the slurry where they go The result ;

Wrong Selection of TBM

If we do not make a good analyse of our ground and do not select the right TBM The result;

CONCLUSION

CONCLUSION

Have a Nice and Shorter

Vacation

Before After

ANY QUESTIONS??