ADVANCED CONSTRUCTION TECHNOLOGY

TUNNEL BORING TUNNEL BORING MACHINEMACHINE

KONE VENKATESH KONE VENKATESH (MT15CTM009)(MT15CTM009)

PRITHVI RAJ. P PRITHVI RAJ. P (MT15CTM019)(MT15CTM019)

SUBMITTED BY:

2INTRODUCTIONINTRODUCTION• Tunnel Boring Machine (TBM) also known as ‘MOLE’.

• It is used to excavate tunnels with a circular cross section.

• It can bore through anything from hard rock to sand.

• Different types of TBMs are used for different geotechnology.

• Used as an alternative to drilling and blasting (D&B) methods and conventional 'hand mining' in soil

• Limits the disturbance to the surrounding ground and produces a smooth tunnel wall.

• Suitable to use in heavily urbanized areas.

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3• TBMs is also a complete single unit moving factory

• Only little finishing work has to be done after using TBMs as this single unit can do

DRILLING SYSTEMS

CONCREATE SPRAYING

SEGMENTAL LINING

ROCK SUPPORTING

PIPE JACKING

CONVEYANCE OF EXCAVATED

MATERIAL

4GEOTECHNOLOGY GEOTECHNOLOGY •The geological and hydraulic information about the soil forms the basis for planning and executing tunneling and pipe jacking projects.

• Provide the basic data for selecting tunneling methods and cutting wheel tools that will cut through the native ground efficiently and economically.

• The most important ground or rock-mechanical parameters for designing a tunnel boring machine are:

-grading curve -rock/clay mineralogy -ground water penetration -quality of the rock -consistency limits -hardness of the rock

5GENERAL PARTS AND SYSTEMSGENERAL PARTS AND SYSTEMS

6CUTTING ROLLSCUTTING ROLLS

•Cutting rolls are used to tear of the soil and rock from tunnel face.

•They are mounted on the cutting heads.

•Different types of materials are used for different ground condition.

•They are placed radially, so as to have maximum efficiency.

•They can revolve themselves in full 360 degree.

•They can be replaced periodically.

•They presses the tunnel face with a force of 26 tons.

7CUTTER HEADS CUTTER HEADS

•Cutter heads is the part of the TBM which faces the ground to be tunneled.

•It will revolve in speed of 1 to 10 rpm

•Cutting rolls and cutting blades are mounted here.

•Cutter head can revolve 360 degree

•They are also provided with openings called muck buckets for extracting excavated materials (chips) to the conveyor.

GRIPPERGRIPPER 8

•Grippers are also called supporting arms of TBMs.

•All TBMs have at least a pair of grippers.

•Grippers provide a radial thrust to the tunnel walls with the help of hydraulic press.

•Grippers are used only when cutter head moves forward against the tunnel face.

9CONVEYORSCONVEYORS•The chips are carried out off the tunnel from the tunnel face via many methods,

-Mechanical transportation Auger conveyor

Conveyor belts

Muck cars

-Hydraulic transportation (slurry circuit)

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10CONVEYORSCONVEYORS•This conveyor system travels in full length of the tunnel.

•Chips are then dumped on disposal plant.

•This keeps the workspace clean and easy to work

11CONCRETE SPRAYER AND BLOCKSCONCRETE SPRAYER AND BLOCKS•In steel arc segmenting, concrete readymade blocks are placed in-between each.

•While in meshing, concrete is sprayed at high pressure by concrete sprayers.

•The concrete sprayer is operated automatically, so that it provide even finishing everywhere.

•Concrete sprayers are fitted behind the gripper section.

•Concrete blocks are placed manually with help of machineries only after the tunneling process is finished.

12PRESS FRAMESPRESS FRAMES

•Press frames are hydraulic piston cylinder arrangement.

•The cutter heads are moved forward due to the extension of pistons.

•The processes stops when the cylinder piston reaches maximum.

13MACHINE TECHNOLOGYMACHINE TECHNOLOGY

• For tunneling project different kind of TBMs are used.

• Type of TBM varies with ground condition.

• Soft ground type

- EPB technology

- Slurry shield

- Mix shield

• Hard ground type

- Single shield TBM

- Double shield TBM

14EPB TechnologyEPB Technology

•EPB is used in soft ground type with less than 7 bar of pressure

•Uses combination of tungsten carbide cutting bits, carbide disc cutters, and/or hard rock disc cutters.

•The EPB gets its name because it is capable of holding up soft ground by maintaining a balance between earth and pressure.

• Also additives such as bentonite, polymers and foam are injected into the ground to further stabilize it.

•Auger conveyor is used to remove chips.

15SLURRYSHIELD &MIXSHIELDSLURRYSHIELD &MIXSHIELD

•In soft ground with very high water pressure and large amounts of ground water, Slurry Shield TBMs are needed.

•Offers a completely enclosed working environment.

•Soils are mixed with bentonite slurry, which must be removed from the tunnel through a system of slurry tubes that exit the tunnel. Large slurry separation plants are needed on the surface for this process, which separate the dirt from the slurry so it can be recycled back into the tunnel.

•For recycling separation plants are used.

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17SINGLE SHIELD TBMSINGLE SHIELD TBM

•Single shield TBMs have no shield as that of in soft ground type.

•Excavation is done by cutter rolls transferred through openings in the cutter head to a belt conveyor, and then to muck cars or conveyor belt.

•There is no excavation chambers as chips are of solid and not as slurry..

•More smoother tunnel walls can be created using single shield TBMs.

18DOUBLE SHIELD TBMsDOUBLE SHIELD TBMs

•These are the most technically sophisticated tunnel boring machines in use.

•This type of machine is ideally suited for drilling long tunnels in hard rock where geological fault zones occur.

•Its main feature is an extendable front shield in the front part of the machine, which allows the cutter head to be extended.

Bertha (Tunnel Boring Machine)o Bertha, also known as Big Bertha, is a 57-foot-

diameter (17.4 m) tunnel boring machineo The biggest Tunnel Boring Machine on Eartho Tunnel Boring Machine built specifically for the

Washington State Department of Transportation's (WSDOT) Alaskan Way Viaduct replacement tunnel project in Seattle.

o Weight : 7,000 tonso Length : 325 feeto Cost : $80,000,000o Tunnel : 9,270 ft. (2,830 m) length o Project Cost : $3.1 billion(estimated)

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22EXTERNAL FEATURESEXTERNAL FEATURES

1) ADVANTAGES

-Is mainly suitable for urban tunneling.

-Less time for completion.

-Total expense is less than any other process.

-Less manual effort is needed.

-Risk factors like explosion, rock slide, etc are less.

2) DISADVANTAGES

-High initial expense.

-Difficult to transport machines.

-Need many skilled technicians.

23CONCLUSIONCONCLUSION

For a fast developing country like INDIA, it is very important to have traffic free transport facilities, underground water supply canal, etc. As these thinks have major part in boosting our economics by foreign investments. The tough task is that to have all this in highly dense metros like Delhi, Mumbai, Bangalore, Chennai, etc. its not possible to build flyovers at all places to as it leads to traffic conjunctions till the project finishes. Also when it come to have transportation across hilly areas time taken and risk factors are more.

To over come this and to provide safe and comfortable transportation in all terrains TUNNELING is the best way to it provide easy tunneling even under huge buildings, tough terrains, under river beds too. It is the best suitable method for a fast developing nation.

24REFERENCESREFERENCES

GOOGLE (www.google.com)

WIKIPEDIA (en.wikipedia.org )

YOU TUBE (www.youtube.com )

HERRENKNECHT TUNNEL SYSTEMS (www.herrenknecht.com)

THE ROBBINS COMPANY (www.robbinstbm.com)

THE MASTERBUILDER construction magazine

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