Non-span-reduction construction method for close-spaced underpass operating railway for loess tunnel with oversized cross section

Abstract

The invention discloses a non-span-reduction construction method for a close-spaced underpass operating railway for a loess tunnel with an oversized cross section. The method comprises steps as follows: firstly, the influence range of the underpass operating railway for the loess tunnel with the oversized cross section is divided into three support grade areas including an I area, an II area and an III area, then construction of a pipe shed working chamber, construction of a pipe shed, backfilling of the pipe shed working chamber and reinforcement by advanced small pipes are performed in sequence, and finally, a three-step and two-step temporary inverted arch method is adopted for hole body excavating and supporting. According to the method, equipment passes through the underpass operatingrailway area safely and rapidly, construction cycle is shortened, cost input is reduced, safety, economic efficiency and reasonability are combined, reference is provided for construction of the sametype of close-spaced underpass operating railway for the loess tunnel with oversized cross section, and construction efficiency of the close-spaced underpass operating railway for the loess tunnel with oversized cross section is further increased, and safety risks of the construction are reduced.

Description

technical field [0001] The invention relates to the field of tunnel construction, in particular to a non-span-reducing construction method for a super-large-section loess tunnel that passes under an operating railway. Background technique [0002] In the construction of loess tunnels close to the operating railway, the construction method mostly adopts the advanced support of the middle pipe shed in the tunnel, the construction of the double side wall pilot pit method, and the reinforcement of the existing railway with military beams. This construction method There are many excavations and procedures in sections, small construction space, large interference in construction procedures, slow work efficiency, long time span, large cumulative deformation, long impact period on railway operation safety, and high safety risks; in small construction space, at the same time When pre-reinforcing the railway track with the military beams during the construction of the existing line, t...

AI Technical Summary

Problems solved by technology

[0002] In the construction of loess tunnels close to the operating railway, the construction method mostly adopts the advanced support of the middle pipe shed in the tunnel, the construction of the double side wall pilot pit method, and the reinforcement of the existing railway with military beams. This construction method There are many excavations and procedures in sections, small construction space, large interference in construction procedures, slow work efficiency, long time span, large cumulative deformation, long impact period on railway operation safety, and high safety risks; in small construction space, at the same time When the railway track is pre-reinforced by the military beam on the existing line construction, there is also a greater safety risk to the railway operation and an increase in the work process

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