Construction method for inverted arch of VI-level water-enriched surrounding rock tunnel

Abstract

The invention belongs to the technical field of tunnel construction, and in particular relates to a construction method for an inverted arch of a VI-level water-enriched surrounding rock tunnel, which aims to solve the problems of low efficiency and high safety hazard in construction of the inverted arch of the VI-level water-enriched surrounding rock tunnel. The construction method comprises the following steps of: reinforcing a tunnel face of a lower bench temporarily, laying a layer of counter pressing rubbles on a to-be-excavated inverted arch section, and constructing steel plate piles on one side close to the tunnel face; excavating a first section of the inverted arch, erecting an inverted arc trestle bridge, and constructing preliminary bracing for the first section of the inverted arc; excavating a second section of the inverted arch, constructing preliminary bracing for the second section of the inverted arch, and meanwhile, constructing a tunnel lining for the inverted arch; filling the constructed inverted arch; and removing the steel plate piles. The construction method provided by the invention has the beneficial effects that the construction safety is high, and the hazard of tunnel face sloughing of the tunnel is lowered effectively; and the method is simple, is easy to organize, and improves a construction progress effectively on the premise of ensuring a safe step pitch.

Description

technical field [0001] The invention belongs to the technical field of tunnel construction, and in particular relates to an inverted arch construction method of a grade VI water-rich surrounding rock tunnel. Background technique [0002] Level VI water-rich surrounding rock tunnels are mostly excavated by the CRD method. According to the relevant requirements of the Ministry of Railways for tunnel safety, the distance between the initial support of the inverted arch and the face of the tunnel shall not exceed 35m, and the excavation footage of the inverted arch shall not exceed 3m per cycle. Therefore, the working face of the inverted arch construction is very close to the face of the lower excavation face. Since the grade VI water-rich surrounding rock is flow-plastic and has no self-stabilization ability, the excavation of the inverted arch is likely to cause the surrounding rock of the face to become unstable, resulting in The face of the palm collapsed. Usually, full-se...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to solve the problems of low efficiency and high safety risks in the construction of the inverted arch of tunnels in Class VI water-rich sur...

Images