Device and method for improving supporting effect of excavation face of earth pressure balance type tunnel boring machine

Abstract

The invention relates to a device and method for improving the supporting effect of an excavation face of an earth pressure balance type tunnel boring machine. The device comprises an exhaust system, a grouting system and an industrial personal computer; the method comprises the following steps that during a shutdown period of a shield tunneling machine, gas pressure P1 in a soil bin is measured through a pressure sensor, meanwhile, the industrial personal computer obtains underground water pressure P2 at the same height, and if P1 is larger than or equal to P2, exhaust and grouting operation does not need to be conducted; if P1 is smaller than P2, the exhaust system is controlled by the industrial personal computer to exhaust gas until gas in the soil bin is completely exhausted; after exhaust is stopped, the grouting system is started through the industrial personal computer, the grouting pressure is set to be P2, the change of the monitored value P1 is observed during grouting, and when the monitored value P1 of the pressure sensor is equal to P2, the grouting system is closed; and after shutdown, P1 and P2 are compared once every 1 h, and when P1 is smaller than P2, the steps S2-S3 are repeated. According to the device and the method, the exhaust system and the grouting system are additionally arranged, operation is convenient, and the construction quality and safety can be effectively improved.

Description

technical field [0001] The invention relates to the technical field of mechanized tunnel excavation construction, in particular to a device and method for improving the excavation face support effect of an earth pressure balance type tunnel boring machine. Background technique [0002] During the construction process of the earth pressure balance tunnel boring machine, the improved muck is used to support and control the deformation of the excavation surface. Foam agent is one of the most commonly used muck modifiers. The foaming agent is mixed with pressurized air to produce a large amount of uniform and stable foam. The foam evenly fills the pores between soil particles under the agitation of the cutter head, which can effectively reduce the internal friction angle of the muck and improve the flow plasticity of the improved muck. But the foam will gradually dissipate with time, and the density of the gas produced after dissipation is much smaller than that of the improved ...

AI Technical Summary

Problems solved by technology

When the gas pressure in the cavity is lower than the groundwater pressure at the same height of the excavation surface, the groundwater will infiltrate into the soil bin, and the soil mass on the excavation surface will also undergo large deformation, which will eventually lead to increased surface settlement, affecting the quality of the project, and in severe cases causing Destruction of surface structures resulting in loss of property and life

At present, there is no solution to this problem on site, and there is no related patent to solve this problem

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