The water leakage and inrush disasters occur from time to time during construction of foundation pit engineering,and improper treatment of groundwater is one of the important factors causing foundation pit accidents.The water inrush accidents often occur in the construction stage such as earth excavation,which is sudden and difficult to visualize.Based on the analysis of on-site measured data and the treatment measures for water inrush accident of a subway station foundation pit engineering in Tianjin,the causes of this accident were reviewed.The main reason is that the effect of pressure relief dewatering in confined aquifer under the base of foundation pit were not obvious.Through the measures of cofferdam reverse pressure,grouting,concrete sealing and so on,and in cooperation with initiating the dewatering well of the confined aquifer outside the foundation pit,the water inrush accident was effectively controlled.During the excavation of foundation pit,the water level inside and outside the foundation pit must be strictly monitored,the causes of abnormalities must be investigated and solved in time,and the field staff must pay more attention.When suspended impervious curtain is adopted for foundation pit and there is no condition for relief well construction in the pit,the observation well outside the pit can be used for pressure relief dewatering,but the large-scale settlement and differential settlement of soil layer in the surrounding environment should be avoided.If necessary,corresponding measures should be taken for protection.
关键词
深基坑工程/止水帷幕/基坑降水/突涌
Key words
deep foundation pit engineering/impervious curtain/foundation pit dewatering/water inrush
维普
万方数据