Deep foundation pit structure above subway tunnel and construction method thereof

Abstract

The invention relates to a deep foundation pit structure above a subway tunnel and a construction method thereof, and relates to the technical filed of deep foundation pits. The deep foundation pit structure comprises a soil layer and a subway tunnel arranged in the soil layer, a pile foundation is arranged in the soil layer, an underpinning beam is poured at the upper end of the pile foundation,a raft is arranged on the underpinning beam, and a shockproof and water proof layer is arranged on the lower plane of the raft. Retaining walls are arranged on the deep foundation pit structure, the inner side walls of the retaining walls abut against the raft, and supporting beams are arranged between the inner side walls. A plurality of separation plates which are distributed in the length direction of the supporting beams are arranged on the raft, each separation plate is located between the two retaining walls which are symmetrical to each other, each separation plate is vertically arranged and perpendicular to the supporting beams, supporting rods are correspondingly divided into a plurality of outer supporting rods, and two ends of each outer supporting rod are correspondingly connected with the corresponding retaining walls or the separation plates. The deep foundation pit structure has the effect of improving the stability of the supporting beams.

Description

technical field [0001] The invention relates to the technical field of deep foundation pits, in particular to a deep foundation pit structure above a subway tunnel and a construction method thereof. Background technique [0002] With the development of urban subways, there are more and more foundation pit projects within the protected area of ​​urban subway tunnels. At present, there are more and more construction examples of deep foundation pits adjacent to urban subways at home and abroad, but there are relatively few construction practices of deep foundation pits above subway tunnels. The deep foundation pit project above the iron tunnel is a high-risk project. The uplift of the pit bottom caused by the excavation of the foundation pit will simultaneously drive the uplift and deformation of the tunnel below, which will cause deformation of the subway tunnel, and the allowable deformation of the subway tunnel is extremely strict; The structure of the deep foundation pit s...

AI Technical Summary

Problems solved by technology

[0004] The applicant found in the follow-up construction project that the above-mentioned technical scheme still has certain defects. Specifically, the area of ​​some deep foundation pits is relatively large, resulting in a large distance between the two retaining walls, so that the The length of each support beam between the retaining walls is relatively large, resulting in poor strength and stability of each support beam, so it needs to be improved

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