【摘要】 支护结构对软土基坑开挖变形具有重要影响,结合深圳某软土深基坑工程实例,通过室内三轴试验测定深圳地区典型海相沉积软土的修正剑桥模型参数,采用FLAC^3D有限差分软件模拟基坑开挖过程,对基坑变形的影响因素进行分析。数值模拟结果表明,在围护结构入土深度、支撑体系刚度、围护结构刚度、锚索预应力几个因素中,对围护结构水平位移影响最大的因素是支撑刚度,对坑外地表沉降影响最大的因素是锚索预应力;提高围护结构刚度能较为显著改善变形,但随着围护结构刚度的增大,这种影响逐渐减小。研究结论可用于软土基坑支护设计优化工作,对同类工程有一定的借鉴作用。更多还原

【Abstract】 The support structure has important influence on the excavation deformation of soft soil foundation pit. Combined with the specific project of soft soil deep foundation pit in Shenzhen,the research determined the Modefied Cam-clay model parameters of typicail marine deposit soft clay through the indoor triaxial test. And using FLAC3 Dsoftware to simulate excavation process. The simulation result show that,in embedded depth,support stiffness,the retention structure stiffness and the anchor cable prestress,the biggest effect factor on level displacement of supporting structure is support stiffness. The biggest effect factor on ground settlement is anchor cable prestress.Improving the retention structure stiffness could significantly improve the deformation,but with the increase of the stiffness of the retaining structure,this effect is gradually reduced. The research conclusion can be used for the design optimization of soft soil foundation pit support,which can be used fot reference for similar projects.更多还原