某复杂地质深基坑止水帷幕渗漏处理案例分析

Case Analysis on the Waterproof Curtain Leakage Treatment in a Complex Geological Deep Foundation Pit

广州番禺某项目地质情况复杂,由回填土、淤泥、粉砂层组成,土质承载力差,地下水极度丰富且有微腐蚀性,基坑深14.35 m,在基坑开挖至12.5 m标高时,突遇粉砂层,止水帷幕漏水漏沙,地面沉降。通过对其原因进行分析探讨,现场采用了“坑内止水、导流、反压、封堵+坑外注浆加固,提前预防处理”的方案进行处理,结果表明该方案不仅能及时有效地解决漏水漏沙情况,确保基坑安全稳定,且该做法也十分经济,达到了经济、适用、安全、可靠的效果,值得推广借鉴。

The geological condition of a project in Panyu,Guangzhou is complex,which is composed of backfill soil,sludge and silt layer with poor soil bearing capacity and extremely rich and slightly corrosive groundwater.The depth of the foundation pit is 14.35 m.When the foundation pit is excavated to to an elevation of 12.5 m,it suddenly encounters a silt layer,causing water and sand leakage in waterproof curtain and ground settlement.Through the analysis and exploration of the causes,the scheme of"water stop,diversion,back pressure,blocking inside the pit+grouting reinforcement,early preventive treatment outside the pit"is adopted on site for treatment.The results show that the scheme can not only solve the problem of water and sand leakage in time and effectively to ensure the safety and stability of the foundation pit,but also be very economical,achieving the effect of economy,application,safety and reliability,which is worthy of promotion and reference.