Wet spraying method of primary support concrete applied to soft surrounding rock tunnels

Abstract

The invention discloses a primary supporting concrete wet spraying method applied to a weak surrounding rock tunnel, and belongs to the technical field of tunnel construction. The method comprises thefollowing steps: an arc steel arch frame is mounted on a rock surface beforehand, and a high-pressure air gun is used for cleaning the rock surface; mortar wets a pipe, and is sprayed to the rock surface; a slump test is performed; a curve path is adopted to finish the concrete spraying of the rock surface in a partition mode: arch top-upper step left arch shoulder-upper step left arch foot-archtop-upper step right arch shoulder-upper step right arch foot-arch top-upper step left arch shoulder-lower step left arc foot-arch top-upper step right arch shoulder-lower step right arch foot; the arch top and arch foot construction is performed in a flow mode, so that procedures are tightly joined, and the construction efficiency and progress are improved; and the accelerator mixing amount in concrete in different areas is gradually increased from bottom to top, so that the concrete spraying disability is guaranteed, the material utilization rate is increased, and the construction cost is reduced. A wet spraying machine is used for operation; other equipment and materials have no need to be added; and constructors are simple and convenient to operate.

Description

technical field [0001] The invention belongs to the technical field of tunnel construction, and in particular relates to a wet spraying method for primary support concrete applied to tunnels with weak surrounding rocks. Background technique [0002] Weak surrounding rock refers to surrounding rock with weak rock quality, low bearing capacity, developed joints and fissures, and broken structure. The structural surface of the body is weak and easy to slide and collapse. During the construction of the tunnel, for the surrounding rocks of grade III, grade IV and grade V, the surrounding rock and the support jointly bear the mountain pressure, so the quality of the initial support of the tunnel is high. However, at present, the initial support of the surrounding rock of this type of tunnel adopts the traditional wet spraying machine operation method in the early stage of construction, and there are problems such as long process time (>12h), high rebound rate, uneven surface, ...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to provide a wet spraying method for primary support concrete applied to tunnels with weak surrounding rocks, aiming at solving the problem of long time-consuming and time-consuming procedures for the primary support of tunnel surrounding rocks in the prior art using traditional wet spraying machines. Technical problems such as high elastic rate, uneven surface, insufficient thickness of shotcrete and insufficient strength to meet design requirements

Images