Large-deformation control construction method for high ground stress weak surrounding rock tunnel

Abstract

The invention discloses a large-deformation control construction method for a high ground stress weak surrounding rock tunnel. A plurality of segments are arranged in the longitudinal extending direction of the tunnel from back to front to construct the constructed weak surrounding rock tunnel. The method comprises the steps that firstly, the rock strength and surrounding rock interior maximum ground stress test is carried out; secondly, the large extrusion deformation grade of the surrounding rock is determined; thirdly, a primary support scheme is determined; fourthly, tunnel excavation and primary support construction are carried out; fifthly, longitudinal tunnel strengthening structure construction is carried out; sixthly, tunnel secondary lining construction is carried out; seventhly, construction of the next segment is carried out according to the first step to the sixth step; and eighthly, the seventh step is repeated many times till the whole construction process of the constructed weak surrounding rock tunnel is finished. According to the method, the steps are simple, the design is reasonable, construction is convenient, and the using effect is good. The tunnel construction process of the high ground stress weak surrounding rock tunnel can be easily, conveniently and rapidly finished, the construction process is safe and reliable, and the large deformation of the weak rock can be effectively controlled.

Description

technical field [0001] The invention belongs to the technical field of tunnel construction, and in particular relates to a large deformation control construction method of a tunnel with high ground stress and weak surrounding rock. Background technique [0002] Tunnel excavation will inevitably lead to the redistribution of the original stress of the surrounding rock. The mechanical behavior of the stress redistribution of the entire surrounding rock can be generalized as the following process: balance. "Looseness" and "looseness" are two completely different concepts in describing the process of stress redistribution, and the manifestations of surrounding rock loads in these two processes are also different. The load generated in the "relaxation" stage is called "deformation pressure". At this time, the reduction of the stress level of the surrounding rock and the deformation of the surrounding rock coexist. From the perspective of rock mechanics, the surrounding rock at t...

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Problems solved by technology

[0018] Third, the large amount of deformation, rapid development and continuous non-convergence, it is very common for the supporting system after construction to be intruded due to poor control of the deformation amount;

[0019] Fourth, the amount of deformation reserved for excavation cannot be scientifically and accurately predicted. If it is too large to increase the excavation section of the tunnel, it will not only be detrimental to the stability of the surrounding rock, but also cause serious waste because the deformation cannot be reached; if it is too small, if the excessive deformation invades limit, resulting in safety risks and waste of replacement

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