A Construction Method for Stopping Water at the Bottom of Underground Excavation Station

Abstract

A construction method for water stop at the bottom of underground excavation station, including construction preparation, construction pilot hole, hole expansion, stirring, rotary spraying, forming rotary spraying mixing pile, constructing the next rotary spraying mixing pile and the pile of previous rotary spraying mixing pile A step in which the sides of the body are occluded with each other to finally form a water-tight curtain. The construction of the pilot hole can adopt the immersed pipe method or the mud retaining wall method, etc. The rotary jet mixing pile at the previous pile position and the pilot hole at the next pile position can be carried out at the same time. The invention completely abandons the dewatering technology of the dewatering well, effectively protects the groundwater resources and solves the problem of water-stopping at the bottom of the station in the water-rich stratum. At the same time, the construction method is simple and flexible, the construction period is short, the stratum is widely applicable, and the controllability is strong. Strong bearing capacity and anti-floating capacity, small construction impact, harmless to the underground environment, and has strong engineering practical value for the construction of low-clearance submerged excavation stations with large areas and high groundwater levels.

Description

technical field [0001] The invention belongs to the field of underground space construction, in particular to a method for stopping water at the bottom of a submerged station. Background technique [0002] The PBA construction method is one of the construction methods commonly used in underground excavation stations. The initial stress system is composed of side piles, central columns, top beams, bottom beams, and top arches, which bear the load during the construction process. layer excavation soil. When the groundwater is relatively rich and the groundwater level is high, this construction method makes there no available water-resisting layer below the excavation range of the foundation pit, so a large area of ​​bottom sealing is required. [0003] At present, my country's subway construction is getting deeper and deeper, and groundwater has become one of the major problems faced by subway construction in many cities. For a long time, a large number of precipitation well...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a construction method for the water stop at the bottom of the underground excavation station, to solve the serious waste of water resources caused by the existing precipitation well technology for the bottom water stop of the underground excavation station, and at the same time, precipitation causes urban ground subsidence, road surface collapse, and building tilting secondary disasters, seriously affecting the technical problems of urban production and life

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