砂性土深基坑开挖与支护变形监测的数值分析  

Sandy Soil Deep Foundation Excavation and Support Deformation Site Monitoring by Numerical Analysis

作　　者：赵秀绍[1] 艾成刚[1] 王旭[1] 郑伟[1] 

机构地区：[1]华东交通大学土木建筑学院,江西南昌330013

出　　处：《河南科技大学学报（自然科学版）》2014年第6期61-65,8,共5页Journal of Henan University of Science And Technology:Natural Science

基　　金：国家自然科学基金项目(51208198);江西省教育厅基金项目(JXJG-13-5-15)

摘　　要：地铁车站深基坑开挖面大、变形控制等级高,而南昌又处在砂性土地区,土层黏聚力较小,与其他地区地质差异较大,基坑开挖与支护可借鉴的经验较少。因此,需要对其变形规律进行研究,为其他车站深基坑设计与施工提供一定的参考。本文以南昌轨道交通某深基坑工程为背景,通过现场实测并结合FLAC3D建立计算模型,对其开挖与支护进行了数值模拟分析,通过计算得出不同开挖阶段的地表沉降、围护桩和周围土壤分层水平位移、轴力的变化规律。研究结果表明:围护桩分层水平位移和轴力以及周围地表沉降直接反映了基坑变形特性,而钢支撑的施加则明显限制了基坑的变形。现场监测结果和数值模拟结果得到的规律基本一致。The deep foundation of metro station has the features of big excavation plane size and high grade of controlling the foundation deformation. Nanchang is in the sandy soil areas with smaller cohesion,so it is different with other areas in geology. There is little experience of deep foundation pit supporting design to learn. Thus,it is necessary to research the deformation law about these to provide a reference for other stations to design and construct the deep foundation. In this paper,taking a deep excavation of Nanchang rail traffic as example,by field measurement and calculation model established by FLAC3 D,the numerical simulation analysis of its excavation and support was made. The different stages of excavation of surface subsidence,supporting pile and soil layering horizontal displacement,axial force variation were calculated. The change law of load bearing of the cables was got. The results show that the deformation characteristics are reflected by envelope pile horizontal displacement,axial force stratification and surface subsidence around the pit directly. The steel support significantly limits the deformation of pit. The calculation results are basically in accordance with the monitoring results.

关 键 词：深基坑 FLAC3D软件 变形规律 现场监测 

分 类 号：U212[交通运输工程—道路与铁道工程]