摘要
软土地层具有孔隙比大、含水量高、压缩性高、强度低、灵敏度高等特性,软土地层条件下深基坑变形一般远超过规范控制值,因此软土地层基坑工程中需要尤其注意支护结构的变形和周围建筑环境的影响。为研究软土深基坑工程在分区开挖中对周边环境的影响,以上海市一例深基坑工程为例采用有限元数值模拟计算分析了软土深基坑开挖对周边环境的影响。分析结果显示:基坑长边附近地表沉降为长槽形,短边附近地表沉降呈现放射形,沉降中心位于沉降坑中靠近基坑的位置;基坑变形空间效应较为明显,基坑阳角部位沉降弱于其他部位,阴角位置沉降更小;随着开挖的进行,地表水平位移的影响范围也在不断扩大,岩土体水平变形所集中的位置而持续下移;开挖进行中,地表水平位移总是集中在基坑周围的2倍开挖深度范围内,岩土体水平变形集中位置基本保持在开挖面的底部附近。
Soft soil layer has the characteristics of large void ratio,high water content,high compressibility,low strength,high sensitivity,etc.The deformation of deep foundation pit under soft soil stratum conditions is generally far more than the control value of the specification.Therefore,special attention should be paid to the deformation of the supporting structure and the impact of the surrounding building environment in soft soil foundation pit engineering.To study the impact of soft soil deep foundation pit excavation on the surrounding environment during zoning excavation,a deep foundation pit project in Shanghai was taken as an example and finite element numerical simulation was used to analyze the impact of soft soil deep foundation pit excavation on the surrounding environment.The analysis results show that the surface settlement near the long side of the foundation pit is in a long groove shape,while the surface settlement near the short side is in a radial shape.The settlement center is located near the foundation pit in the settlement pit;The spatial effect of foundation pit deformation is relatively obvious,with weaker settlement at the external corners of the foundation pit compared to other parts,and smaller settlement at the internal corners;As the excavation progresses,the influence range of surface horizontal displacement is also continuously expanding,and the location where the horizontal deformation of the rock and soil mass is concentrated continues to move downwards;During excavation,the horizontal displacement of the surface is always concentrated within the range of 2 times the excavation depth around the foundation pit,and the horizontal deformation concentration of the rock and soil is basically maintained near the bottom of the excavation surface.
作者
宋卓华
任宝双
郁志伟
孙志国
SONG Zhuohua;REN Baoshuang;YU Zhiwei;SUN Zhiguo(CCCC Construction Group Co.,Ltd.,Beijing 100022,China;Research and Development Center on Green Building Technology,CCCC,Beijing 100022,China)
出处
《建筑结构》
北大核心
2023年第S02期2488-2493,共6页
Building Structure
基金
中交集团科技研发重大项目(2021-ZJKJ-11)。
关键词
软土地层
数值模拟
深基坑
环境影响
分区开挖
soft soil stratum
numerical simulation
deep foundation pit
environmental impact
zone excavation
