非平衡荷载下城市轨道交通车站深基坑变形特性分析  

Analysis of Deformation Characteristics of Deep Foundation Pit in Urban Rail Transit Station under Unbalanced Load

作　　者：刘涛 姜磊 王申 彭红国 李岩 LIU Tao;JIANG Lei;WANG Shen;PENG Hongguo;LI Yan(The Third Engineering Co.,Ltd.of China Railway Seventh Group,710032,Xi’an,China)

机构地区：[1]中铁七局集团第三工程有限公司,西安710032

出　　处：《城市轨道交通研究》2024年第3期59-64,69,共7页Urban Mass Transit

基　　金：中国中铁股份有限公司科技研究开发计划项目(2019014)。

摘　　要：[目的]目前城市轨道交通非平衡荷载作用导致的地下工程病害、事故逐渐增多。为了解非平衡荷载对城市轨道交通车站深基坑变形的不利影响,减小施工风险,需要对该类型荷载作用下车站深基坑变形特性进行分析。[方法]基于理论分析和现场监测数据,研究了非平衡荷载下城市轨道交通车站深基坑的变形特性,分析了围护桩变形、深层土体水平位移及地面沉降的变化规律,探讨了围护桩变形同深层土体水平位移、地面沉降及开挖深度之间的关系。[结果及结论]围护桩水平位移曲线呈鱼腹状,且地层条件对围护桩变形影响明显;围护桩变形和深层土体水平位移大致呈线性关系,其中经验系数取1.30;由于偏载作用,深基坑周边地面沉降较大,围护桩最大水平位移δ_(hm)与地面最大沉降δ_(vm)存在δ_(vm)=(0.9~3.0)δ_(hm)的关系,且两者之间的比例系数大于对称荷载作用下的数值;岩层较强的抵抗变形能力限制了围护桩变形,δ_(hm)与H_(e)存在δ_(hm)=(0.009%~0.060%)H_(e)的关系,且两者之间的比例系数小于对称荷载作用下的数值;深基坑施工对周边环境影响区域主要划分为1区(主要影响区)、2区(次要影响区)和3区(无影响区),基坑施工影响区域约为(0~2.5)H_(e)。[Objective]At present,the underground engineering diseases and accidents caused by unbalanced load in urban rail transit are increasing gradually.In order to understand the adverse effect of unbalanced load on the deformation of deep foundation pit in urban rail transit station and reduce the construction risk,it is necessary to analyze the deformation characteristics of station deep foundation pit under unbalanced load.[Method]Based on theoretical analysis and on-site monitoring data,the aforementioned deformation characteristics are studied,the changing law regarding the retaining pile deformation,the horizontal displacement of the deep soil and ground settlement is analyzed,and the interrelation between the retaining pile deformation and the deep soil horizontal displacement,the ground settlement and excavation depth is discussed.[Result&Conclusion]The horizontal displacement curve of the retaining pile is fish-belly shaped,and the formation condition has obvious influence on the deformation of the retaining pile.There is a roughly linear relationship between the deformation of the retaining pile and the horizontal displacement of deep soil,and the empirical coefficient is proposed to be 1.30.Due to partial load,the ground settlement around the deep foundation pit is larger,and the relationship between the maximum horizontal displacement δ_(hm) of the retaining pile and the maximum ground settlementδvm is δ_(vm)=(0.9~3.0)δ_(hm),and the proportional coefficient between them is greater than the value under symmetric load.The strong deformation resistance of rock strata limits the deformation of the retaining pile.There is a relationship of δ_(hm)=(0.009%~0.060%)H_(e) between δ_(hm) and H_(e),and the proportional coefficient between them is smaller than the value under symmetric load.The impact area of deep foundation pit construction on the surrounding environment is mainly divided into Zone 1(main impact zone),Zone 2(secondary impact zone)and Zone 3(no impact zone),and the impact area of foundation pit co

关 键 词：城市轨道交通 车站 深基坑 变形特性 非平衡荷载 

分 类 号：U231.3[交通运输工程—道路与铁道工程]