Construction method of interval tunnel at bridge-tunnel connection position close to existing railway

Abstract

The invention discloses a construction method of a section tunnel at the bridge-tunnel connection position close to an existing railway. The construction method comprises the following steps that a step method is adopted for tunneling from one end of the section tunnel to the bridge-tunnel connection end; constructing an external protection structure between the railway and the mountain; a step method is converted into a CRD method to continue tunneling; cRD method tunneling is stopped, and the tunnel face is closed; excavating a platform pilot tunnel on the closed tunnel face; the platform pilot tunnel is supported; a working platform is formed through transverse expanding excavation; constructing a supporting structure at the joint of the bridge and the tunnel; the interval tunnel is tunneled to the bridge-tunnel connecting position; constructing an open cut tunnel portal and a bridge structure of the interval tunnel; and dismantling the external protection structure. A novel construction scheme is provided, the technology that a shed frame operation platform is arranged below a slope at the bridge and tunnel connecting position is changed, in the construction process, the construction risk can be greatly reduced, the construction step sequence is simplified, the engineering investment is reduced, the influence on a railway below a broken foot is reduced, the application range is wide, and the method can be suitable for any bridge and tunnel connecting mode.

Description

technical field [0001] The invention relates to the technical field of tunnel construction, in particular to a construction method of an interval tunnel at the connection between bridges and tunnels adjacent to an existing railway. Background technique [0002] Adjacent to the existing railway means that the railway is located at the foot of the slope, and the bridge-tunnel connection of the new construction is located on the hillside above the railway, which requires the new construction to intersect the railway on the plane. [0003] In addition, the connected section of the bridge and tunnel of the interval tunnel has the characteristics of complex structure, cumbersome construction sequence, extremely high construction risk, and difficult construction organization. The conventional practice is to construct pile foundations on both sides of the railway under the slope, and set up scaffolding on the upper part of the pile foundation to completely cover the railway, and set...

AI Technical Summary

Problems solved by technology

[0007] However, this patent adopts a penetrating central pilot hole structure similar to the previous patent, and its construction method is still cumbersome and complicated

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