A rapid construction method for double trestle bridges with simultaneous detonation of three steps in tunnels with weak surrounding rocks

Abstract

The invention discloses a rapid construction method of a tunnel under a soft surrounding rock condition, which aims at solving the problem that the existing construction process is difficult to meet the stipulation of a safe step pitch under the soft surrounding rock condition; meanwhile, a soft surrounding rock tunnel is larger in deformation and needs to constructed and closed rapidly, however,the actual construction effect is barely satisfactory, and an accident easily happens. Therefore, for the problems, millisecond vibration-reducing blasting is achieved by utilizing a digital detonator, the disturbance to a surrounding rock is reduced, and the smooth future construction is guaranteed; due to the use of a double-trestles inverted arch movable framework, lapping positions are alternatively changed through the two trestles innovatively, a pair of trestles is always used for travelling of vehicles in a construction process, and the problem of disturbance to step excavation and inverted arch construction is solved, so that the construction efficiency is greatly improved. Through adoption of related equipment and a construction process in the method, the strict stipulation of thesafe step pitch can be met, and the construction efficiency of the tunnel can be remarkably improved while the construction safety of the soft surrounding rock tunnel is enhanced.

Description

technical field [0001] The invention belongs to the field of tunnel engineering, and in particular relates to a rapid construction method for tunnels under weak surrounding rock conditions. Background technique [0002] As a common unfavorable geological condition, weak surrounding rock is often encountered in tunnel construction. The three-step subdivision excavation method is a common method for constructing tunnels under weak surrounding rock conditions. In the traditional three-step excavation method construction scheme, the upper, middle and lower steps are excavated step by step from top to bottom, and the tunnel Inverted arches generally lag behind the step construction process and are constructed separately, which inevitably affects the entry and exit of personnel, machinery and dregs at the excavation face, and affects the efficiency of construction. In addition, under the regulation of safe step distance, there are strict requirements on the distance between the s...

AI Technical Summary

Problems solved by technology

The three-step subdivision excavation method is a common method for constructing tunnels under weak surrounding rock conditions. In the traditional three-step excavation method construction scheme, the upper, middle and lower steps are excavated step by step from top to bottom, and the tunnel Inverts generally lag behind the steps in the construction process and are constructed separately, which inevitably affects the entry and exit of personnel, machinery and dregs on the excavation face, and affects the efficiency of construction

In addition, under the regulation of safe step distance, there are strict requirements on the distance between the second lining and the inverted arch from the face of the tunnel; the weak surrounding rock is easily disturbed and deformed greatly. security incident

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