Support method for releasing hard level surrounding rock high ground stress through buffering layer

Abstract

The invention provides a support method for releasing hard level surrounding rock high ground stress through a buffering layer. The support method comprises the following step one of carrying out construction preparation; the step two of adopting a borehole-blasting method for carrying out excavation construction; the step three of installing the buffering layer and a preliminary support; the stepfour of carrying out deformation monitoring; the step five of carrying out backfill grouting; and the step six of carrying out secondary lining construction. The method has the excellent effects thatfirstly, operation is easy, raw materials are low in price, the method does not need to consume too much manpower and too many material resources, and cycling time is short; secondly, too strong support parameters are not needed, the building cost is low, the problem that due to the hard level surrounding rock high ground stress, the preliminary support of a tunnel cracks and deforms can be effectively solved, and safety and stability of the support structure are ensured; and thirdly, by means of the buffering layer with the suitable thickness, the surrounding rock can be allowed to restrain,the stress of the surrounding rock is released, the load which the support needs to bear is reduced, the restraining amount of the surrounding rock can be limited, and thus the surrounding rock doesnot generate plastic deformation.

Description

technical field [0001] The invention belongs to the technical field of high ground stress tunnel construction, and in particular relates to a support method for releasing high ground stress of hard horizontal surrounding rock through a buffer layer. Background technique [0002] The initial stress field of surrounding rock is composed of gravity stress and tectonic stress. The former is in the vertical direction, while the latter is mostly in the horizontal direction, and is in a relatively stable and balanced state. After the excavation of the cavern is completed, the surrounding rock is released from the constraints at the excavation boundary and deforms, causing stress redistribution and forming a secondary stress field. After the support is completed, the support and the surrounding rock deform together to form the tertiary stress field of the surrounding rock. The initial stress field of surrounding rock is given by R c / σ max Evaluation, when the ratio is less than ...

AI Technical Summary

Problems solved by technology

[0003] In order to solve the problem of cracking and deformation of the initial support of tunnels with high ground stress in hard horizontal surrounding rock, the present invention provides a support method for releasing high ground stress in hard horizontal surrounding rock through a buffer layer. The support method of the present invention includes the following steps:

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