Discussion on Accident of Foundation Excavation of Xianghu Station of Hangzhou Subway No.1 Line Again

In the paper,some discussions on accident of foundation excavation of Xianghu Station of Hangzhou subway No.1 line are proposed from construction,design and management.Some questions are proposed about codas concerned with building foundation excavation and its applications.It is indicated that constructors have important blame in the accident.In the design of the engineering,there are mistakes.For example,in analyses of stability against overturning of retaining structure,overall stability by Swedish circle method and stability against heaving of pit bottom,if the CU shear strength parameters of saturated clay are adopted,the resistant force has to be calculated by buoyant unit weight rather than by saturated unit weight of soil.The high sensitive of clay is not paid enough attention.It is an important fault that the Fengqing road is not closed during the construction.