Collapsible loess tunnel primary support arch replacement construction method

Abstract

The invention provides a collapsible loess tunnel primary support arch replacement construction method. The method comprises the five steps of carrying out arch replacement construction preparation, temporary measures, soil body reinforcement, primary support steel arch frame pre-reinforcement and arch replacement construction. According to the construction method, a special lining construction rack does not need to be additionally arranged, operation is carried out based on a waterproof plate trolley, rapid construction is facilitated, and the cycle operation time is shortened. Soil body reinforcement and steel arch frame pre-reinforcement are brought into the construction procedure, the safety of operators can be guaranteed, the danger of soil body chipping or collapse in an arch frame dismantling process is effectively avoided, and meanwhile the bearing capacity, integrity and waterproof and anti-permeability performance of tunnel surrounding rock bodies are guaranteed. By adoptingthe arch replacement construction method for construction, the geological problems of collapsible loess tunnel arch crown settlement, peripheral convergence and the like can be effectively solved, thetunnel quality problems of secondary lining cracking, beyond limit and the like caused by large deformation of surrounding rock are prevented, the construction cost is effectively reduced, and the construction period is effectively shortened.

Description

technical field [0001] The invention belongs to the field of tunnel engineering construction, and in particular relates to a construction method for changing the primary support of a collapsible loess tunnel. Background technique [0002] Collapsible loess is a kind of soil with loose structure, uniform soil quality and self-weight collapsibility. As a kind of special soil quality, it is widely distributed in the northwest of my country. The Dikengyuan Tunnel in the southward movement of National Highway 310 is located in Shanzhou District, Sanmenxia City, in the collapsible loess strata. [0003] Due to the special properties of collapsible loess, the geological environment of the tunnel is complex, and the stability of the surrounding rock is poor. During the construction of the tunnel, the settlement is difficult to control, the primary support is deformed, and the excessive convergence of the surrounding rock causes the secondary lining encroachment and longitudinal cra...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to solve the technical problems existing in the prior art. The purpose of the present invention is to provide a construction method for initial support and arch replacement of collapsible loess tunnels, so as to solve the problem that one-time initial support cannot effectively prevent the collapse of collapsible loess tunnels. Large deformation behavior of rock

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