摘要
该文通过天津某基坑工程,开展了SMW工法基坑围护结构的桩身深层水平位移和坑周地表沉降等内容的系统安全监测测试,分析了天津软土基坑工程中SMW桩围护结构的变形规律,探讨了SWM工法基坑监测的有效警戒指标及信息化施工的安全控制标准。采用有限元法考虑基坑分步开挖与围护全过程,模拟和研究了基坑开挖时围护墙的变形、坑外土体变形的基本特征。研究表明:围护结构的变形模式为悬臂式和抛物线型组合形态,最大变形位置位于距桩顶8.5m左右,即第二道支撑下1.5m左右,该位置处于较为软弱的淤泥质软土层中。基坑外地面沉降显示为"凹槽型"变形形式,沉降变形的影响在3倍基坑深度内。基坑外最大地面沉降位置距离坑边约0.5~0.55倍坑深。分析结果可为天津及类似地质情况的基坑工程中采用SMW工法桩提供借鉴。
In this paper,through a foundation pit project in Tianjin,the systematic safety monitoring test of the deep horizontal displacement of the pile and the surface settlement around the pit of the foundation pit retaining structure of SMW engineering method is carried out,the deformation law of the SMW pile retaining structure in Tianjin soft soil foundation pit project is analyzed,and the effective warning index of SWM engineering method foundation pit monitoring and the safety control standard of information construction are discussed.Considering the whole process of step-by-step excavation and retaining of foundation pit,the basic characteristics of retaining wall deformation and soil deformation outside the pit during foundation pit excavation are simulated and studied by finite element method.The research shows that the deformation mode of the retaining structure is a combination of cantilever and parabola,and the maximum deformation position is about 8.5 m away from the pile top,that is,about 1.5 m under the second support,which is in the relatively weak muddy soft soil layer.The ground settlement outside the foundation pit shows a"groove"deformation form,and the influence of settlement deformation is within 3 times the depth of the foundation pit.The maximum ground settlement outside the foundation pit is about 0.5~0.55 times the pit depth from the pit edge.The analysis results can provide reference for SMW engineering method pile in foundation pit engineering in Tianjin and similar geological conditions.
作者
霍知亮
温淑荔
孟庆林
谭儒蛟
郎瑞卿
Huo Zhiliang;Wen Shuli;Meng Qinglin;Tan Rujiao;Lang Ruiqing(School of Civil Engineering,Tianjin University;Tianjin Municipal Engineering Design and Research Institute Co.,Ltd.;China Railway 18 Bureau Group Co.,Ltd.;Key Laboratory of Soft Soil Engineering Characteristics and Engineering Environment of Tianjin)
出处
《勘察科学技术》
2021年第5期16-20,共5页
Site Investigation Science and Technology
基金
天津市自然科学基金项目(19JCQNJC06900)
关键词
基坑开挖
地表沉降
SMW工法
安全监测
有限元
foundation pit excavation
ground settlement
SMW engineering method
security monitoring
finite element
