Advance support construction method for high-strength pipe shed of tunnel

Abstract

The invention discloses an advance support construction method for a high-strength pipe shed of a tunnel. A process for carrying out advance support construction on a pipe shed of one segment of a constructed tunnel comprises the following steps: (1) constructing support arches and guide pipes; (2) installing a drilling machine and a grouting machine in place; (3) carrying out advance support construction on the pipe shed: (301) preparing before drilling; (302) drilling pipe joints at front ends and synchronously grouting; (303) connecting the pipe joints; (304) continuously drilling and synchronously grouting; (305) repeating the steps (303) and (304) many times until the drilling processes of pipes of the current constructed pipe shed are finished; (306) blocking drill holes; (307) carrying out grouting construction on final holes; (308) repeating the steps (301) to (307) many times until all advance support construction processes of the pipes of the pipe shed are finished; and (4) carrying out excavation construction on the tunnel. The method disclosed by the invention is simple in step, reasonable in design, simple and convenient in construction and good in support effect; and by adopting automatic drilling type high-strength pipes of the pipe shed, the advance support process of the tunnel can be simply, conveniently and quickly finished.

Description

technical field [0001] The invention belongs to the technical field of tunnel advance support construction, and in particular relates to a tunnel high-strength pipe shed advance support construction method. Background technique [0002] The advance support of the pipe shed is to drive a group of steel pipes (i.e. pipe shed pipes) into the ground along the outer side of the excavation contour of the tunnel, and combine them with the steel arch to form a powerful pre-support reinforcement system for the shed. , to support the load from the surrounding rock on the upper part of the pipe shed, and pressurize the grout into the formation through the grouting hole to strengthen the weak and broken formation and improve the self-stabilization ability of the formation. [0003] At present, in the construction of tunnel engineering, the construction of the pipe shed mainly adopts the construction method of leading hole jacking. Specifically, the drilling rig is used to drill the hole...

AI Technical Summary

Problems solved by technology

During actual construction, the approach hole jacking method has the following problems: First, there are many construction procedures, the process connection is complicated, the construction period is long, the flexibility is poor, and the length and parameters of the advance support are difficult to carry out according to the actual drilling construction conditions. Timely adjustment is required, and a professional operation team is required for construction; second, after the pipe shed is installed in place, low-pressure grouting is used, and the grout diffusion radius is small, making it difficult to form a large-scale reinforcement ring; third, holes are opened on the pipe shed, due to the The reason for the opening of the pipe body of the shed is that the grout fills the proximal end first, blocking the exhaust channel, resulting in air pockets at the far end and top of the pipe shed, and the grouting cannot be full; Fourth, the construction area with poor self-stabilization ability of the surrounding rock , easy to collapse holes, difficult to jack into the pipe shed

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