Construction method of oblique forward and bias pressure shallow buried tunnel entry arch

Abstract

The invention belongs to a construction method for the right-angle skew tunnel-entering cover arch of an unsymmetrical-loaded and shallow-buried tunnel. In the method, conventional cover arches and steel arches are erected by adopting a left and right staggered erecting method, that is, the erecting direction of the steel arches and the slanting direction of the axial lead of a tunnel traveling axial lead form an angle of 45 to 60 degrees, the steel arches at a left side end and the steel arches at the right side end are erected in a staggered manner, the distance between the adjacent steel arches which deviate from the right side of a mountain is smaller than the distance between the adjacent steel arches which are close to left side of the mountain, the distances between the steel arches within a range of 20 to 30 m in a hole are adjusted, a conventional orthogonal cover arch is manufactured into a cover arch which is in the right-angle skew with a tunnel-entering direction. The method provided by the invention can ensure smooth and safe hole entering of an unsymmetrical-loaded and shallow-buried tunnel in a narrow tunnel portal topographic condition, the amount of soil stone excavated from a mountain body can be greatly reduced, the construction resources are saved, environmental protection is facilitated, and the method has the advantages that the method is simple and practical, labor and time are saved, the construction cost is low, the construction period is short, the effects of safety and reliability are realized, and high efficiency and good quality are achieved.

Description

technical field [0001] The invention belongs to a construction method of an oblique normal bias pressure shallow buried tunnel entry arch. Background technique [0002] At present, the construction method of tunnel arching is to use large-scale manpower and material resources to cut and excavate the mountain outside the tunnel to form a construction site that is conducive to the operation of large-scale machinery. The cutting plane should be perpendicular to the driving axis of the tunnel and the area of ​​the mountain section should be larger than the cross-sectional area of ​​the tunnel arch. A certain distance in the tunnel forms a stable working surface in the tunnel. This traditional tunnel arch construction method requires a large amount of excavated earth and rock, labor and time-consuming, high construction cost, long construction period, slow speed and low efficiency. [0003] In particular, if the construction site is a narrow mountain on the outside (away from t...

AI Technical Summary

Problems solved by technology

This traditional tunnel arch construction method requires a large amount of excavated earth and rocks, labor and time-consuming, high construction cost, long construction period, slow speed and low efficiency.

[0003] In particular, if the construction site is a narrow mountain on the outside (away from the mountain side) and wide on the inside (close to the mountain side), the construction terrain of the tunnel entrance arch is seriously biased, or the tunnel entrance arch The construction site is located on a steep slope of the mountain, and the tunnel entrance direction is obliquely cut with the mountain, resulting in a shallow buried depth on the side of the mountain near the river, and a serious bias on the side near the mountain, and the entrance position of the tunnel entrance is extremely narrow. For a construction site with an operating platform, if the traditional construction method is still adopted, the amount of earth and rocks to be cut and excavated will be larger, more labor-intensive and time-consuming, the construction cost will be greater, the construction period will be longer, the speed will be slower, and the efficiency will be lower.

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