Soft rock tunnel construction method based on flexible formwork support

Abstract

The invention discloses a soft rock tunnel construction method on the basis of flexible formwork support. A soft rock tunnel is divided into a plurality of segments from back to front to be subjected to construction. Construction of any one segment comprises the following steps that (1), basic mechanical parameters of surrounding rocks are defined; (2), the tunnel reserved excavating quantity is defined; (3), the tunnel begins to be excavated; (4), A tunnel support structure is defined: the tunnel support structure comprises a tunnel incipient support structure, a flexible formwork support structure and tunnel two-time linings; (5), tunnel incipient support is constructed; (6), the flexible formwork support is constructed; (7), the tunnel two-time linings are constructed; (8), a next segment is constructed; and (9), step (8) is repeated for many times until all the construction processes of the soft rock tunnel are completed. According to the soft rock tunnel construction method on the basis of the flexible formwork support, the method and the steps are easy, design is reasonable, achieving is convenient, and the using effect is good; and the reserved excavating quantity is defined according to deformation conditions of the surrounding rocks of the soft rock tunnel, the flexible formwork support structure is adopted to support full cross sections of the tunnel and subjected to coordination deformation with the tunnel incipient support structure, and thus structure stability of the tunnel two-time linings is guaranteed.

Description

technical field [0001] The invention belongs to the technical field of tunnel construction, and in particular relates to a soft rock tunnel construction method based on flexible form support. Background technique [0002] In recent years, with the rapid development of my country's highway and railway construction, the construction of soft rock tunnels under the conditions of large buried depth and high ground stress has become one of the inevitable trends in the development of the transportation field. Wushaoling Tunnel, Zhongnanshan Tunnel and Xiakou Tunnel, etc. Due to the harsh engineering geological conditions, the self-supporting capacity of the surrounding rock is poor, and the deformation of the soft rock tunnel is severe. If the support is not timely or the plan is unreasonable, large deformation of the surrounding rock and damage to the lining structure will easily occur. For this reason, a large number of experts, scholars and on-site engineering technicians have c...

AI Technical Summary

Problems solved by technology

In fact, for large-deformation soft rock tunnels under specific geological conditions, even the 120mm upper limit reserved deformation allowed by the code cannot meet the requirements of continuous deformation of soft rock after initial support, and the strain energy of surrounding rock cannot be fully released. Eventually lead to the failure of the steel arch and the instability of the surrounding rock

So far, there is still a lack of comprehensive theoretical research on the reserved deformation system for excavation of large-deformation soft rock tunnels.

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