某主动土压力不平衡深基坑的设计实践

Design and Practice of a Deep Foundation Pit Under Unbalanced Active Earth Pressure

以南京河西地区某软土深基坑为例,介绍了由于场地地形高差较大引起主动土压力不平衡带来的支护结构设计时内力取值偏小、变形不协调等设计难题。通过支撑系统顶冠梁与腰梁分开设置、支护构件内力综合分析取值、结合主体结构设计增设换撑等针对性处理措施,解决了上述设计难题。施工期间监测数据表明对支护结构采取的措施保证了支护结构及周边环境的安全,取得了良好的效果。

Using a deep foundation pit of Nanjing in soft clay,the supporting structure design difficulty,such as the value of internal force is smaller than that in practice and the deformation is compatible with the earth pressure because of the unbalanced active earth pressure caused by the uneven terrain of ground surrounding are introduced.Via the methods of setting up the capping beam and waling separately in the supporting system,adopted comprehensive analysis to internal force of retaining and protection structure,adding support replacement combined with underground structure,those design problems are successfully solved.Monitoring data shows that the proposed measures can ensure the safety of the supporting structure and the surrounding environment,and a better result has been achieved in practice.