桩锚支护坑中坑开挖稳定性及围护结构受力变形特性研究  

Stability of Pit Excavation and the Stress and Deformation Characteristics of Envelope Structure in Long Pit with Pile-Anchor Support

作　　者：罗贤民 黄勇 蒙强 徐前卫[3] 谢金利 LUO Xianming;HUANG Yong;MENG Qiang;XU Qianwei;XIE Jinli(Guangxi Nanning Airport Comprehensive Transportation Hub Construction Co.,Ltd.,Nanning Guangxi 530048,China;Construction Project Headquarters of Guangxi Airport Management Group,Nanning Guangxi 530048,China;College of Transportation Engineering,Tongji University,Shanghai 201804,China)

机构地区：[1]广西南宁机场综合交通枢纽建设有限公司,广西南宁530048 [2]广西机场管理集团建设工程指挥部,广西南宁530048 [3]同济大学交通运输工程学院,上海201804

出　　处：《工程质量》2023年第6期21-28,共8页Construction Quality

摘　　要：长大坑中坑的施工具有相当的危险性,以南宁GTC工程23m深的坑中坑为研究背景,利用有限元法结合现场实测的方法研究桩锚支护体系下长大坑中坑的开挖稳定性。研究结果表明:①全断面整层开挖时,围护结构的侧移超出控制值;②基坑从中间往两边分两层开挖时,坑壁土体最大水平位移接近控制值11mm;③增大锚索直径可显著减少围护结构侧移;④开挖前期,一层护坡坡顶附近地表土受到的扰动更大,随着土体卸荷作用对边坡的扰动不断加强,开挖完成后,最大侧移发生的位置转移至15m深度处。The construction of a pit in a large pit is quite dangerous.Taking a pit in a pit with a depth of 23 meters in Nanning GTC Project as the research background,the excavation stability of a pit in a large pit in a pile and anchor supporting system is studied using the finite element method combined with the field measurement method.The results show that:①the lateral displacement of the envelope exceeds the control value during the excavation of the whole section and the whole floor;②when the foundation pit is excavated in two layers from the middle to both sides,the maximum horizontal displacement of the soil is close to the control value of 11mm;③Increasing the diameter of anchor cable can significantly reduce the lateral displacement of enclosure structure;④in the early stage of excavation,the disturbance of the surface soil near the top of the first layer of slope protection is greater.As the disturbance of the slope is continuously strengthened by soil unloading,the position where the maximum lateral displacement occurs shifts to a depth of 15m after the completion of excavation.

关 键 词：基坑工程 桩锚支护体系 坑中坑开挖 数值模拟 

分 类 号：TU753[建筑科学—建筑技术科学]