Tunnel Boring Machine Slurry Separation System
Tunnel Boring Machine Slurry Separation System through muddy water pressure balance model not only can effectively use the mud to stabilize the excavation surface strata, but also prevent the collapse at the same time, through the mud wall formed by the effective prevention of gushing water, and through the simultaneous grouting can be very Good control of the surface subsidence and to avoid the occurrence of segment leakage, which can ensure that the ground environment, ground buildings from the impact of tunnel construction.
Tunnel Boring Machine Slurry Separation System on the shield of environmental protection in the construction of mud treatment has a very important role.
On hard grounds or rocky grounds two types of TBMs are used. Open type TBMs or Shielded tunnel boring machine separator. Excavation of hard rock is carried out by disc cutter fitted in cutter head of TBMs.
These generate compressive stress that leads to crackers or fractures in the earth. This excavated earth or rock is called muck, which is passed through holes between the cutter head to the conveyor belt and then is exited out of the machine.
Open type tunnel boring machine separator do not have any shield, thus the area behind the head depends on rock for support. Gripper system helps the machine to advance forward. But not every machine can move continuously with the help of gripper like the Wirth machine, in such cases the machine moves ahead with help of thrust gained against grippers.
Open type tunnel boring machine separator do not excrete cement segment behind them like other machines. The tunnel rock is supported by rings beams, shot rete, steel straps, rock bolts, ring steel, etc.
In cases where rocks are prone to fracture shielded hard rock tunnel boring machine separator are used.
These unlike open type excrete concrete segments which support the fractured unstable parts of the tunnel. There are two modes in double shield tunnel boring machine separator.
These use the tunnel walls for grip in stable conditions to move ahead. In fractured rock cases, the thrust of the gripper is used to move forward. This prevents the thrust forces damaging the already fragile walls of the tunnel.
Same method is followed by single shield tunnel boring machine separator but can be useful only in fractured ground cases because the move ahead only after being pushed by the segments of concrete excreted behind in the tunnel.