A Supporting Method for Large-Section Soft Rock and Large-deformation Tunnel

Abstract

A support method for large-section soft rock and large-deformation tunnels. After excavating a foot, the primary shotcrete is drilled, and the first restraint rod is sent into the hole, and the first restraint rod is grouted to form the upper primary Lining support; under the support of the upper primary lining, initial spraying of concrete is carried out after the middle steps are excavated in dislocation on both sides; Spray concrete after descending the steps; send the third restraining rod into the hole after drilling, and backfill the left and right sides of the lower step; excavate the core soil part reserved for the middle step and the lower step, and then excavate Arch, the construction of the next cycle, and the tunnel penetration. In the support method of the present invention, the support type is changed from the inner support to the outer support, which saves space in the tunnel, ensures the safety and durability of the support structure, and effectively controls the large deformation of the tunnel, and is more safe, economical, durable and easy to operate. Strong, effectively shorten the construction period.

Description

technical field [0001] The invention relates to the field of tunnel engineering, in particular to a support method for large-section soft rock large-deformation tunnels. Background technique [0002] my country is a country with many mountains and hills, among which mountains and hills account for 69% of the country's land area. The construction of transportation infrastructure will also develop rapidly, and a large number of soft loose surrounding rock tunnels will inevitably be encountered during the construction of highways and railways. When tunnels are built in soft and loose strata, the self-stability of the surrounding rock is poor, and slumping and traction deformation are prone to occur, and the deformation is large, lasting for a long time, and rheological characteristics are obvious. The initial support structure of the tunnel is prone to problems such as cracking, falling blocks, steel frame distortion, breaking and encroachment under the action of large extrusi...

AI Technical Summary

Problems solved by technology

[0004] (1) The cost of the project is high, the process is cumbersome, the progress is slow, and the construction period is extended;

[0005] (2) The effect of controlling large deformation of soft rock is mediocre, or even ineffective;

[0006] (3) The secondary lining is often constructed when the deformation of the initial support structure has not converged, and the stress on the secondary lining is relatively large, so the reliability, safety and durability of the tunnel structure cannot be guaranteed;

[0007] (4) Without considering the stability of the initial support structure, blindly strengthening the strength and stiffness of the initial lining, the support effect is poor, and the economic efficiency of the tunnel project is poor

Images