成都某基坑渗水事故分析及处理  

Analysis and Treatment of a Deep Excavation Seepage Induced Hazards in Chengdu

作　　者：彭莹 PENG Ying(Chengdu Xingshu Engineering Survey and Design Group Co.Ltd.,Chengdu 610070)

机构地区：[1]四川兴蜀工程勘察设计集团有限公司,成都610070

出　　处：《土工基础》2023年第6期841-844,851,共5页Soil Engineering and Foundation

摘　　要：基坑渗水导致基坑变形,将严重威胁基坑安全,出现渗水现象时,基坑周边变形明显,应立即启动应急预案防止变形扩大。以成都某基坑渗水事故为例,介绍并分析了发生基坑渗水原因、处理措施及效果。在基坑因为渗水出现险情时,应及时封堵渗水点,并对桩间土采取压力注浆,但是因出水量大,基坑侧壁粘性土已被水泡胀,部分水玻璃被冲走,注浆效果不明显,桩间土变形严重时,应及时采取回填反压,待桩间土稳定后再进行施工。抢险结果表明,采用的注浆加反压土的综合处理措施效果明显,相关经验可为同类工程设计及事故处理提供有益借鉴。When the unexpected seepage in the deep excavation site results in the excessive deformation of the excavation supporting structure,which might seriously threaten the excavation safety.When this unexpected seepage occurs,the excessive deformation adjacent to the supporting structures is often obvious.This paper presents a case history of the mitigation of a seepage induced accident in Chengdu.The factors that might cause the unexpected seepage,seepage mitigation measures and results are also discussed in the paper.When the seepage induced hazard occurred,the seepage locations should be immediately sealed by using the pressure grouting with water glass into soils in-between the solder piles.Due to the large amount of seepage,the results of the pressure grouting might not have the expected results since the cohesive soils at the excavated walls were soaked and softened,so that the water glass could be washed away.When the large deformations at the excavation side walls,the backfilling measure should be used followed by the pressure grouting after the soil movements are stabilized.The mitigation results indicated that the pressure grouting with water glass plus the backfilling are an effective way of mitigating the unexpected seepage induced hazards.

关 键 词：基坑渗水 双液注浆 基坑抢险 回填反压 

分 类 号：TU473[建筑科学—结构工程]