敏感环境条件下深基坑支护设计与实践

Design and Practice of Deep Foundation Pit Support Technology under Sensitive Environment

中心城区基坑工程除满足自身强度、变形控制要求外,还须保证周围的建(构)筑物的正常使用要求。中山南路B4地块项目位于上海繁华商业中心,基坑面积约1万m2,开挖深度为14.2~15.2m。基坑采用"地下连续墙+三道水平砼支撑"的总体顺作法方案,在此基础上,通过采用两墙合一地下连续墙、地墙替代结构边桩、双半圆环结合中部对撑的支撑布置形式、设置施工栈桥等技术措施,在确保基坑及周边建(构)筑物安全的同时,节省了工程造价,加快了塔楼工期,解决了本工程施工场地紧张的难题。实测数据表明,本基坑实施方案能够有效控制基坑变形。

In addition to meeting its own strength and deformation requirements,the foundation pit project in the central city must also ensure the normal use requirements of surrounding buildings.The Zhongshan South Road B4 block project was located in the prosperous commercial center of Shanghai.The foundation pit area was about 10,000 m^2,and the excavation depth was 14.2~15.2 m.Diaphragm Wall with three levels horizontal RC strut were used to support the deep excavation.Technical measures including dualpurpose diaphragm wall,diaphragm wall instead of structural side piles,double semi-circular RC Struts were also adopted.While ensuring the safety of foundation pits and surrounding structures,the design scheme at the same time saved the project cost,speeded up the construction period of the tower,and solved the problem of the tight construction site of this project.The measured data showed that this foundation pit implementation plan could effectively control the deformation of the foundation pit.