一种无中板大型地下泵站深基坑支护换撑技术

A Support Replacement Technology for Deep Foundation Pit supporting of Large Underground Pumping Station without Medium Plate

南淝河中游重点排口初雨污染控制工程建于合肥市南淝河两岸,北起滨河路与和平路交口,南至滨水公园。在滨水公园处(巢湖南路与铜陵路交叉口)建设一座埋深22.5 m的大型雨水泵站,采用灌注桩结合五道钢支撑支护体系开挖施工,该泵站结构无中层板,原拆撑方案采用“闷拆法”施工,即泵站结构全部完成后再拆除,施工过程中侧墙钢筋需穿越钢支撑构件,施工情况复杂,会对结构防水及混凝土浇筑质量产生隐患。经研究讨论及理论计算后,拆撑方案优化为利用现有腰梁及结构中隔墙进行换撑,该方法大大缩短了施工工期,且保证了主体结构施工质量,可给其他类似工程提供一定参考。

The primary rainwater pollution control project at the middle reaches of the South Feihe River was built at both sides of the South Feihe River in Hefei City.This project starts from Binhe Road-Heping Road Intersection at the north to Binshui Park at the south.A 22.5-m deep large rainwater pumping station was built at Binshui Park(South Chaohu Road-Tongling Road Intersection).This project was excavated and constructed by using the cast-in-place piles combined with steel five-support supporting system.The structure of this pumping station has no medium plate.The original support demolition scheme adopts the"closed demolition method"for construction.In other words,the structures of pumping station will be dismantled after all completed.in the construction process,the rebar of side wall should pass through the steel support members.The construction situation is complex,which will cause the hidden danger to the waterproof of structure and the pouring quality of concrete.After the study,discussion and theoretical calculation,the support demolition scheme is optimized to use the existing waist beam and structural middle partition for support replacement.This method greatly shortens the construction period,and guarantees the construction quality of the main structure,which can be referenced for the other similar projects.