Twin-arch tunnel middle pilot tunnel vault backfilling construction method

Abstract

The invention provides a twin-arch tunnel middle pilot tunnel vault backfilling construction method. The method comprises the following steps that a middle pilot tunnel is excavated, and a support is constructed; after the middle pilot tunnel is excavated and the support extends forwards by a certain distance, a left pilot tunnel is excavated, and a support is constructed; after the middle pilot tunnel is excavated to a certain depth, a middle partition wall is poured; an in-the-hole drill is arranged in position, drill holes are formed, and the drill holes are led to a middle pilot tunnel vault space in the top of the middle partition wall from the left pilot tunnel or a right pilot tunnel; a conveying pipe is installed in the drill holes so that sprayed concrete can enter the middle pilot tunnel vault space in the top of the middle partition wall; twin-arch tunnel middle pilot tunnel vault backfilling construction is achieved. Backfilling of the middle pilot tunnel vault is conducted in the manner that upper steps of the left pilot tunnel are drilled to form the holes. The technical problem that under the working condition that pouring of the middle partition wall is conducted in two directions, the middle pilot tunnel vault can not be backfilled is solved, middle pilot tunnel vault backfilling and middle partition wall pouring are conducted at the same time, and the effective working time is shortened greatly.

Description

technical field [0001] The invention relates to the construction field of double-arch tunnels, in particular to a construction method for backfilling a pilot tunnel vault in a double-arch tunnel. Background technique [0002] Due to the constraints of the design structure of the double-arch tunnel itself and the limitation of the force system, the excavation and support of the upper steps of the main tunnel can only be carried out after the pouring of the central partition wall and the backfilling of the vault are completed. That is, firstly, the excavation and initial support of the intermediate pilot tunnel are carried out from the entrance and exit; secondly, the pouring of the intermediate partition wall is carried out in one direction from the entrance to the exit or from the exit to the entrance after the intermediate pilot tunnel is penetrated; Three, the backfilling of the vault of the central pilot tunnel follows the pouring of the central partition wall from the en...

AI Technical Summary

Problems solved by technology

[0004] When the excavation of the central pilot tunnel and the initial support have not been completed, the pouring of the central partition wall from the middle of the central pilot tunnel to the entrance or exit conflicts with the backfilling construction of the central pilot tunnel vault, that is, the reinforcement of the central partition wall is bound and the trolley is in place. Processes such as moving, concrete pouring and backfilling construction of the pilot tunnel vault interact with each other and cannot be carried out at the same time

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