某临河基坑止水帷幕失效案例分析  

Case Study on Waterproof Curtain Failure of A Foundation Pit Adjacent to A River

作　　者：浦春林 李苏春[1] 刘晖[2] 

机构地区：[1]江苏省纺织工业设计研究院有限公司,江苏苏州215128 [2]中铁建工集团有限公司,江苏苏州215009

出　　处：《水利与建筑工程学报》2015年第2期158-161,共4页Journal of Water Resources and Architectural Engineering

摘　　要：基坑工程中,对常规止水帷幕失效的原因分析、研究很多,但对临河基坑的止水帷幕失效案例分析甚少。临河基坑因其所处的特殊周边环境及地质条件,止水帷幕的失效有其特殊原因。以苏州市某临河基坑止水帷幕的失效为案例并结合监测成果进行分析,研究表明,止水帷幕失效的原因为施工前未进行清障导致三轴搅拌桩止水帷幕垂直度受影响进而影响帷幕的搭接长度;临河侧基坑主动区有限土体主动土压力的减少使围护体系受力不平衡,围护体呈现"S"形变形进而剪切止水帷幕。针对上述原因分析,总结了避免临河基坑止水帷幕失效的针对性措施,可供同类基坑围护结构设计及施工时参考。There are rich studies on conventional waterproof curtain failures in excavation engineering,but rarely on the cases which are adjacent to the rivers. The failures of the waterproof curtains in these foundation pits have their special causes,due to their specific surrounding environment and geological conditions. Based on a case study of the waterproof curtain failure in a foundation pit near the river in Suzhou,the failure mode was analyzed combining the monitoring data. It is found that the obstacles were not cleared out before the construction of the tri-axial mixing pile which influenced the verticality of the pile and then the lap length of the curtain. In addition,the reduction of active earth pressure of some limited soils in active area of the pit caused uneven stress on the retaining system,which led to the ＂S＂shape deformation of the system,and in turn the incision of the retaining body into the waterproof curtain. According to the analysis of the above mentioned reasons,the control measures to avoid waterproof curtain failure in these pits were summarized,which would provide some reference for structural design and construction of similar pits.

关 键 词：临河基坑 止水帷幕 清障 深层水平位移 高压旋喷桩 

分 类 号：TV223.43[水利工程—水工结构工程]