A Supporting Method for High Ground Stress Soft Rock Highway Tunnel

Abstract

The invention discloses a high-ground stress soft rock highway tunnel supporting method. The high-ground stress soft rock highway tunnel supporting method comprises the steps of: A. excavating upper steps, and carrying out anchor-plate retaining construction; B. erecting second I-shaped steel supports for the upper steps after ending anchor-plate retaining; C. building foamed concrete buffer layers for the upper steps; D. carrying out secondary injection concrete construction on the upper steps; E. excavating lower steps and erecting first I-shaped steel supports for the lower steps, and spraying concrete; F. pouring plastic concrete into the lower steps; G. erecting second I-shaped steel supports for the lower steps, and spraying the concrete; H. carrying out secondary lining construction on the lower steps; J. backfilling inverted arches; and K. carrying out secondary lining construction on the upper steps, that is, determining the erection position of a formwork by measurement lofting, carrying out arch crown backfill grouting by the concrete having the same grade with a tunnel lining, and dismantling a plug mold after the strength of the arch crown concrete is satisfied. The high-ground stress soft rock highway tunnel supporting method has an obvious effect on control on large deformation of a soft rock tunnel under a high-ground stress, is simple, convenient and easy and is simple in operation and low in cost.

Description

technical field [0001] The invention relates to the technical field of road tunnel construction, in particular to a method for supporting road tunnels in high ground stress soft rock. Background technique [0002] The terrain and geological conditions in western China are complex, and a large number of bridge and tunnel projects are encountered in the construction of high-grade highways. Due to the special geological and topographical conditions, long tunnels with weak surrounding rocks that pass through areas of high geostress and have harsh engineering geological environments have emerged in recent years, which has brought major challenges to the design and construction of long expressway tunnels. The biggest problem in high ground stress soft rock tunnel engineering is the structural design, construction and later maintenance of the soft rock tunnel. The prominent features of these tunnels are weak surrounding rock, high ground stress, high pressure-intensity ratio, larg...

AI Technical Summary

Problems solved by technology

At present, conventional support measures are difficult to adapt to the large deformation requirements of soft rock tunnels. During the construction process, the primary and secondary linings are frequently cracked and damaged. After support, the tunnel deformation exceeds the limit and requires continuous renovation. Seriously affect the construction progress, increase the construction cost, and bring more safety hazards to the construction, and the construction quality of the tunnel is difficult to guarantee

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