CFG桩复合地基条件下基坑围护结构变形分析  

Analysis on Deformation of Foundation Pit Retaining Structure under the Condition of CFG Pile Composite Foundation

作　　者：贺腾飞 HE Tengfei(Shanghai Urban Construction Design&Research Institute(Group)Co.,Ltd.,Shanghai 200125,China)

机构地区：[1]上海市城市建设设计研究总院(集团)有限公司,上海200125

出　　处：《路基工程》2021年第5期186-191,共6页Subgrade Engineering

基　　金：上海市科学技术委员会科研计划项目:中浅层地下空间承载力综合影响技术研究(19DZ1200903);软土地区零覆土大尺度无工作井盾构隧道设计技术研究(18DZ1205102)。

摘　　要：以珠海某地下通道基坑工程为背景,研究CFG桩复合地基整体抗压、抗剪强度的相关参数,通过理论计算结果、有限元计算结果与监测数据的对比,进行不同CFG桩复合地基参数对围护结构变形的影响研究。结果表明:CFG桩复合地基的加固作用,不仅体现在控制土体竖向沉降,还可减小土体侧向变形;采用复合地基整体强度计算方法确定的参数进行有限元计算,计算值与监测值吻合度较高;增大CFG桩复合地基加固宽度、加固深度,可有效减小围护结构变形,但加固宽度、加固深度分别大于2倍、2.5倍基坑开挖深度后,影响作用不再显著。Based on the foundation pit works of one road tunnel in Zhuhai,the relevant parameters of overall compressive strength and shear strength of CFG pile composite foundation are studied.By comparing the theoretical calculation results,the finite element calculation results and the monitoring data,the influence of parameters of different CFG pile composite foundation on the deformation of the retaining structure is analyzed.The results show that the reinforcement effect of CFG pile composite foundation is not only reflected in controlling the vertical settlement of soil,but also reducing the lateral deformation of soil.The parameters determined by the overall strength calculation method of composite foundation were used for finite element calculation,and the calculated values were in good agreement with the monitored values.Increasing the reinforcement width and depth of CFG pile composite foundation can effectively reduce the deformation of the retaining structure.However,when the reinforcement width and the depth are respectively greater than 2 times and 2.5 times of the depth of the foundation pit excavation,the influence of expanding the reinforcement scope on the control of the deformation of the retaining structure is no longer significant.

关 键 词：CFG桩 复合地基 基坑 围护结构 变形 

分 类 号：U459.3[建筑科学—桥梁与隧道工程]