上海世博500kV地下变电站圆形深基坑逆作法变形与受力特性实测分析

上海世博500kV地下变电站是直径为130m的深埋圆筒形全地下结构，采用全逆作法施工。针对基坑工程特点，基坑开挖期间建立了全过程、全方位的监测系统，完整地记录了施工过程中围护结构的变形与内力和周边环境的变形。监测数据表明：围护结构的侧向变形明显小于相同开挖深度的其它基坑工程，地下连续墙呈现以水平受力为主的圆形结构特点，体现了圆形基坑环向受力的特点和利于变形控制的优点。该工程各项监测数据均在允许值范围之内，验证了相关设计参数的合理性和理论研究的正确性，为软土地区类似深基坑工程的设计和施工提供参考和借鉴。

Analysis of monitored displacement and stress of deep cylindrical structure for the 500kV World Expo Underground Transmission and Substation project during excavation by top-down method

The 500kV World Expo Underground Transmission and Substation was a deep cylindrical excavation with a diameter of 130 m.The excavation depth for the project was 34m and it was constructed in difficult soft soil condition.The foundation pit was constructed successfully by top-down method.Systematic monitoring was carried out during the whole process of excavation.The monitoring system recorded the displacements of retaining wall and bearing capacity of structure completely.Monitoring data show that the later...