Subway foundation pit large-span support system and construction method thereof

Abstract

The invention relates to a subway foundation pit large-span support system and a construction method thereof. The system comprises horizontal truss support units horizontally supported between underground diaphragm walls of a foundation bit. The horizontal truss support units are uniformly distributed in parallel and at an interval along length and height directions; and each horizontal truss support unit comprises an upper-plane truss support, a lower-plane truss support and connecting rods vertically connected between the upper-plane truss support and the lower-plane truss support. The construction method comprises the following steps of during a construction process, installing one horizontal support unit at a designed elevation, then excavating a corresponding soil body in layers, utilizing a guide rail to drop the other horizontal support unit to a designed elevation through a lifting power device, excavating a corresponding soil body in layers again, and repeating the steps until finishing construction of a basement. The subway foundation pit large-span support system and the construction method thereof are suitable for earth excavating construction of the deep foundation pit; in addition, the horizontal support units adopt spatial truss structures so as to be high in structural strength; and the support system is adopted to meet the requirements on stability and deformation control of the subway foundation pit, and has the characteristic of large span at the same time.

Description

technical field [0001] The invention relates to the field of subway foundation pit construction, in particular to a support body and a construction method thereof. Background technique [0002] At present, the main supporting system used for subway foundation pits is mainly reinforced concrete and steel pipe support. In addition, the traditional support strength cannot meet the needs of large-span subway foundation pits. In addition, based on the narrow and rectangular plane shape of subway station buildings, the earthwork excavation of subway foundation pits is generally carried out by step-back excavation relay method. Due to the tight spacing of the horizontal supports and the small construction area, earthwork excavation machines often use excavation equipment with small bucket capacity to complete earthwork excavation through step relay, which greatly reduces the efficiency of earthwork excavation; on the other hand, When the steel pipe supports are hoisted one by one,...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a large-span support system for a subway foundation pit and its construction method, to solve the technical problems of small support span and low structural strength of the existing foundation pit; and to solve the problem of low construction efficiency

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