Three-step inverted arch synchronous excavation and support construction method for soft surrounding rock tunnel

Abstract

The invention discloses a three-step inverted arch synchronous excavation and support construction method. During tunnel construction, an upper step (1), a middle step (2), and a lower step (3) synchronously tunneling and synchronously supporting, and the lower step (3) excavation comprises an inverted arch (4); the construction comprises the following steps that excavating is carried out, specifically, three-step synchronous drilling, synchronous charging and line connecting are carried out, and detonating is sequentially carried out according to the upper, middle and lower sequences; supporting is carried out, specifically, deslagging and supporting are carried out according to the upper, middle and lower sequences; spraying is carried out, specifically, concrete spraying is sequentiallycarried out from bottom to top; in the excavating and supporting steps, a long-arm excavator is adopted to directly lift and transfer a tool and a material on a backfill hole slag (7) to the upper step (1); and in the spraying step, a long-arm wet-spraying manipulator is adopted to directly spray concrete on the upper step (1) on the backfill hole slag (7). According to the three-step inverted arch synchronous excavation and support construction method, the operation advantages of the long-arm construction machines are fully utilized, the procedure of building a transport channel is simplified between steps, the construction progress is obviously accelerated, and the three-step inverted arch synchronous excavation and support construction method is suitable for the construction of a softsurrounding rock tunnel three-step method.

Description

technical field [0001] The invention relates to a method of excavating a tunnel. Background technique [0002] The three-step method is one of the most commonly used construction methods for tunnels with weak surrounding rocks. The traditional three-step method usually excavates and supports step by step in the order of the upper step, the middle step, and the lower step. Repeatedly building and clearing the transportation channels required for transporting tools and materials between the lower steps, the process is complicated, and the cycle time is long, which seriously affects the construction progress; The support often lags behind the upper and middle steps, and the initial support is closed and looped late, which is not conducive to the deformation control and safe construction of the tunnel with weak surrounding rock. [0003] Chinese patent CN 109723445 A discloses a full-section tunneling method for parallel three-step tunnels. The problems in this patent are that ...

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Problems solved by technology

[0004] The technical problem to be solved by the present invention is to provide a three-step construction method for rapid excavation and support of weak surrounding rock tunnels, so as to overcome the existing three-step excavation technology with many procedures, slow construction progress, and ring formation of initial support. Disadvantages such as late

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