Construction method of open-cut subway tunnel across fault

Abstract

The invention discloses a construction method of an open-cut subway tunnel cross a fault. The construction method comprises the steps that a tunnel pit is excavated in an area across the fault, a tunnel lining is poured in the tunnel pit, and the tunnel pit is filled with soil. The construction method is characterized in that the tunnel lining is poured in the tunnel pit specifically as follows: the tunnel lining is poured in the tunnel pit with fiber concrete section by section, wherein a 10-20 cm deformation joint (3) is arranged between every two sections of the tunnel lining, the length ofthe sections of the tunnel lining within a fracture zone (1) of the fault is 5-10m, the length of the sections of the tunnel lining in a transition zone (2) of the fault is 8-15m, the cross section of the tunnel lining is in the shape of an arch with an arched upper part and a rectangular lower part, the arched upper part is in arc transition with the rectangular lower part, and the depth-span ratio of the arched upper part is 1 / 5-1 / 12. The open-cut subway tunnel constructed through the construction method has good anti-dislocation performance and anti-seismic performance.

Description

technical field [0001] The invention relates to a method for constructing an open-cut subway tunnel. Background technique [0002] At present, with the continuous advancement of subway construction, subway tunnel projects that cross active faults continue to appear. The dislocation of active faults (serious dislocation is earthquake) will seriously affect the stability and safety of tunnel engineering, resulting in damage or destruction of tunnel structure. [0003] Existing subway tunnels are divided into open-cut tunnels and underground tunnels according to the excavation method: the excavation method of the open-cut tunnel is to dig the ground first to form an open-air tunnel pit, and then build a tunnel structure in the tunnel pit ( lining), and then cover and backfill; open-cut tunnels are suitable for the construction of shallow buried tunnels and suburban tunnels. The excavation method of the submerged tunnel is to drill holes into the interior of the soil, then dig...

AI Technical Summary

Problems solved by technology

This is because the open-cut method destroys the inherent structure of the soil itself more, and the structural strength of the backfill soil is low, resulting in a decrease in the overall structural strength of the open-cut tunnel and its surroundings.

In addition, the cross-section of the open-cut subway tunnel is rectangular, which has the advantages of high utilization rate of tunnel space and convenient construction. However, the stress concentration at the corners and the middle of the top of the open-cut tunnel makes it vulnerable to active fault dislocation and earthquakes. more serious damage

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