止水帷幕对软黏土基坑抗隆起稳定性的影响分析  

Analysis on the influence of waterproof curtain on heave-resistant stability of excavations in soft clay

作　　者：李瑛[1] 张金红 刘兴旺[1] 陈东[1] 李冰河[1] LI Ying;ZHANG Jin-hong;LIU Xing-wang;CHEN Dong;LI Bing-he(Zhejiang Province Institute of Architectural Design and Research,Hangzhou 310006,China)

机构地区：[1]浙江省建筑设计研究院,浙江杭州310006

出　　处：《地基处理》2019年第3期29-32,共4页Journal of Ground Improvement

摘　　要：对深厚软黏土地区的深基坑工程,围护桩插入比很大时也可能发生隆起失稳事故,工程实例表明土体会从围护桩间流动。针对排桩和止水帷幕的支护结构,采用绕止水帷幕底的圆弧滑动模式,根据极限平衡法推导得到坑底抗隆起稳定分析公式。通过对隆起失稳基坑实例分析,证明软黏土基坑抗隆起稳定分析不仅要考虑排桩入土深度而且要考虑止水帷幕入土深度,作为附加要求,建议绕止水帷幕底抗隆起稳定安全系数应大于1.1。分析忽略了排桩对桩间软黏土的摩阻力,结果偏于安全。In soft clay foundation,soil may flow from the gaps between row piles during excavation,and this may cause an adverse impact on heave-resistant stability.Assuming that the soil slip failure mode was a circular around the bottom of waterproof curtain,a formula based on limit equilibrium method was deduced and adopted to analyze the heave-resistant stability of excavations.Furthermore,the influence on heave-resistant stability of excavations caused by the embedded depth of waterproof curtain was discussed.It is shown that the heave-resistant stability of excavations would overestimate the safety against basal heave when using the traditional method with the circular placed around the bottom of pile.The collapse of the excavation in Huzhou showed that the waterproof curtain was too short to resist the soft clay movement between row piles.Hence,the method in this paper can be used to calculate the embedded depth of waterproof curtain in soft clay foundation.

关 键 词：深基坑 止水帷幕 抗隆起稳定 软黏土 

分 类 号：TU470[建筑科学—结构工程]