岩溶发育区地铁穿越断裂带基坑承压水突涌应急处理技术

Emergency Treatment Technology of the Rush of Foundation Pit Confined Water for the Subway passing through Fractured Zones in Karst Development Area

岩溶发育区地铁穿越断裂破碎带时,基坑开挖施工中坑底极易发生突涌风险,严重影响地铁线路施工的安全及进度。以某穿越断裂破碎带的地铁车站深基坑开挖工程为例,详细分析总结了断裂破碎带引发承压水突涌风险的原因,并针对性地提出了坑内蓄水临时抢险措施及设置隔水层、综合注浆处理的整治方案。基坑抽水试验表明基坑内因断裂破碎带裂隙产生的过水通道得到了有效封堵。采用基坑外侧注浆切断断裂破碎带引起的涌水通道,并结合基坑内垂直分层注浆封堵坑内涌水点的综合注浆法,可有效解决岩溶发育区穿越断裂破碎带基坑的承压水突涌问题,成果可为岩溶发育区基坑承压水突涌的应急处理提供技术参考。

For the construction of subway passing through fractured zones in karst development area,it is easy to cause the rush of confined water during the excavation,and it will seriously affects the safety and schedule of the construction of the subway.Combined with the excavation project of a subway station passing through the fractured zone in China,the factors of the rush of the confined water caused by the fracture were analyzed,and the temporary rescue measures for water storage in the pit,isolation plan for waterproof curtain and improvement plan for the comprehensive grouting method were further proposed,respectively.The pumping tests show that the water channels caused by the fractured zones are effectively sealed.The comprehensive grouting method consists of grouting outside the pit and vertical layered grouting in the pit.The water inflow channel can be cut by grouting and the gushing water point can be sealed by the vertical layered grouting.The comprehensive grouting method can effectively solve the rush of confined water problem.The results can provide a technical reference for the emergency treatment and control of the rush of the confined water in Karst development area during the excavation.