Construction method for controlling deformation of anchor piles at barrel segment of tunnel

Abstract

The invention provides a construction method for controlling deformation of anchor piles at a barrel segment of a tunnel. The construction method comprises the following steps of: dividing a section of a tunnel to be excavated into three parts, i.e. an upper step, a middle step and a lower step, firstly, excavating the part of the upper step to an in-depth M-meter position of the barrel segment, and arranging supporting steel frames and locking anchor pipes, which are used fora primary support, at intervals; based on the upper step, excavating the part of the middle step to an in-depth N-meter position of the barrel segment, and arranging the supporting steel frames and the locking anchor pipes, which are used for the primary support, at intervals; obliquely inserting reinforcing anchor pipes downwards into tunnel rock mass of the barrel segment at the part of the middle step; based on the middle step, excavating the part of the lower step and arranging the supporting steel frames and the locking anchor pipes, which are used for the primary support, at intervals. Compared with the prior art, in the construction method for controlling deformation of the anchor piles at the barrel segment of the tunnel, which is provided by the invention, the longitudinal rigidity and bearing capacity of the primary support are reinforced, integral sinking, deformation and fracture of a cavern primary support system are controlled, and construction safety and tunneling efficiency of the tunnel are ensured.

Description

technical field [0001] The invention relates to the technical field of tunnel construction, in particular to a construction method for controlling deformation of anchor piles in tunnel body sections. Background technique [0002] The construction of tunnels is in the ascendant in my country, especially in the central and western regions of China, where the construction scale of roads and railways is still far from enough to meet the actual needs. However, there are many hills, mountains, and debris flows in the central and western regions, and the geological characteristics have the remarkable characteristics of "four poles and three highs": extremely strong terrain cutting, extremely complex and active tectonic conditions, extremely weak and broken lithological conditions, and extremely significant seismic effects; stress, high seismic intensity, and high risk of geological disasters. At the same time, most of the central and western regions are natural scenic areas and th...

AI Technical Summary

Problems solved by technology

[0004] 1. After the construction of the initial support of the middle steps, due to the dislocation of the connecting plates of the front and rear arch feet due to uneven settlement, cracks of different degrees appear locally on the surface of the initial support;

[0005] 2. The phenomenon of "concave curvature" appears in the local rock mass at the lower part of the connecting plate of the middle step;

[0006] 3. The cavern support system in the tunnel body is prone to overall subsidence

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