软土基坑抗隆起稳定性计算的改进

在软土深基坑设计中,基坑抗隆起验算是一项重要的验算。首先介绍了不同的情况下基坑抗隆起稳定性的典型计算方法。然后引入基坑形状、围护墙入土深度、坑底下软土深度、坑底被动区地基加固处理及基坑内工程桩对基坑抗隆起稳定性的影响,并且介绍了相应的计算改进方法,为计算抗隆起稳定性提供了更为合理的方法。最后通过对新加坡Clarke Quay地铁站入口基坑开挖工程实例验算表明,计入各有利因素的影响,抗隆起稳定安全系数由0.6增加到1.528,证实了改进计算方法的合理性,同时也得出当坑底以下软土深厚时,联合使用坑底地基加固和工程桩能比较有效的提高抗隆起稳定性。

Improvement on basal heave stability analysis for excavations in soft clay

Evaluation of basal heave stability is one of important design checks for excavations in soft clays.Two typical approaches for basal heave stability analysis were first introduced.Then the effect of some influence factors on basal heave stability was presented and reasonable corrections were proposed for these various factors.These factors include excavation shape,wall penetration depth,thickness of soft clay below excavation,soil improvement below excavation base and foundation piles inside excavation.Finally,the basal heave stability of a successful excavation with 3 mm measured base heave at the entrance of Clarke Quay Station in Singapore was evaluated,the factor of safety was increased from 0.6 by the typical method to 1.528 by the improved method.It reveals that combination of the soil improvement below excavation base and foundation piles inside excavation could be an effective way of increasing the basal heave stability for excavations in soft clay.