31-01-2012, 01:08 PM
TUNNEL BORING MACHINE
TUNNEL BORING MACHINE.pptx (Size: 1.42 MB / Downloads: 250)
Introduction
A tunnel boring machine (TBM) consist of 1 or 2 shields (Large metal cylinders).
At the end of dhe shield, a cutting wheel is attached.
Behind the cutting wheel, there is a chamber and inside it there is a set of hydraulic jacks which push the TBM forward.
Behind the shield, ie at the finished part of the tunnel several support mechanisms such as control rooms, rails for dirt pemoval, slurry pipelines etc., can be set up.
Hard Rock TBM
In hard rocks either shielded type or open type TBM can be used. For an open type TBM, no shield will be there.
The TBM’s disc cutters create compressive stress fractures and causes the rock to chip away. The chipped rock particles are called muck. Muck is removed through openings in cutter disc to conveyer belt system, which removes it from the tunnel.
Facility to lay supports such as ring beams, steel strips, wire mesh etc., are provided in Hard Rock TBM.
Tunnel Boring Machine Facts
Propel & Grip system:
This section performs 2 critical functions. It prevent the machine from sliding backward and also helps its forward movement.
Conveyor System: It transports rock fragments to the tail end of the tunnel boring machine, and From there these excavated material are transferred to rail cars which take them outside the tunnel.
Types of tunnels
Public works tunnels:
Public works tunnel carry water, sewage or gas lines across great distances.
Tunnel construction
Workers use two methords in tunnel construction. Fullface mode and top-heading and bench mode.
In top-heading and bench mode they first bore a small tunnel , and then we bore underneath it. By this we can understand the stadility of rock before moving far forward.
TUNNEL BORING MACHINE.pptx (Size: 1.42 MB / Downloads: 250)
Introduction
A tunnel boring machine (TBM) consist of 1 or 2 shields (Large metal cylinders).
At the end of dhe shield, a cutting wheel is attached.
Behind the cutting wheel, there is a chamber and inside it there is a set of hydraulic jacks which push the TBM forward.
Behind the shield, ie at the finished part of the tunnel several support mechanisms such as control rooms, rails for dirt pemoval, slurry pipelines etc., can be set up.
Hard Rock TBM
In hard rocks either shielded type or open type TBM can be used. For an open type TBM, no shield will be there.
The TBM’s disc cutters create compressive stress fractures and causes the rock to chip away. The chipped rock particles are called muck. Muck is removed through openings in cutter disc to conveyer belt system, which removes it from the tunnel.
Facility to lay supports such as ring beams, steel strips, wire mesh etc., are provided in Hard Rock TBM.
Tunnel Boring Machine Facts
Propel & Grip system:
This section performs 2 critical functions. It prevent the machine from sliding backward and also helps its forward movement.
Conveyor System: It transports rock fragments to the tail end of the tunnel boring machine, and From there these excavated material are transferred to rail cars which take them outside the tunnel.
Types of tunnels
Public works tunnels:
Public works tunnel carry water, sewage or gas lines across great distances.
Tunnel construction
Workers use two methords in tunnel construction. Fullface mode and top-heading and bench mode.
In top-heading and bench mode they first bore a small tunnel , and then we bore underneath it. By this we can understand the stadility of rock before moving far forward.