基于HS-Small模型软土基坑开挖过程三维数值分析  

3D Numerical Analysis of Soft Soil Foundation Pit Excavation Process Based on HS-small Model

作　　者：孙海忠 邓捷程 SUN Haizhong;DENG Jiecheng(Shanghai Construction Design&Research Institute Co.,Ltd.,Shanghai 200235,China;Department of Geotechnical Engineering,College of Civil Engineering,Tongji University,Shanghai 200092,China)

机构地区：[1]上海市建工设计研究总院有限公司,上海200235 [2]同济大学土木工程学院地下建筑与工程系,上海200092

出　　处：《建筑施工》2022年第6期1373-1376,共4页Building Construction

摘　　要：基于上海某项目的基坑围护方式,根据国内外学者对上海地区软土做的大量土工试验和国外学者的取值经验,使用Plaxis 3D中的HS-Small本构模型模拟土层,建立了三维基坑数值模型,分析其在开挖过程中围护结构的水平侧移和坑外土体的沉降变形特性。结果表明,基坑围护墙随围护墙深度呈现先增大后减小的趋势,在1倍挖深附近取得最大值;坑外地表沉降值随边界距离增大呈现先增大后减小的趋势,且在1倍挖深处最大,在4倍挖深距离处几乎无影响。将围护墙侧移计算结果与技术规范计算值进行对比,表明HS-Small模型计算的围护结构侧移值比技术规范计算值小,支撑薄弱的地方相差值较大。Based on the foundation pit support mode of a project in Shanghai,according to a large number of geotechnical tests done by domestic and foreign scholars on the soft soil in Shanghai and the value taking experience of foreign scholars,the HS-Small constitutive model in Plaxis 3D is used to simulate the soil layer,and a 3D foundation pit numerical model is established to analyze the horizontal lateral displacement of the retaining structure and the settlement and deformation characteristics of the soil outside the pit during the excavation process.The results show that,the retaining wall of foundation pit increases first and then decreases with the depth of retaining wall,and the maximum value is obtained near one time of excavation depth;the surface settlement outside the pit increases first and then decreases with the increase of boundary distance,and the maximum value is at one time of excavation depth,and there is almost no effect at four times of excavation depth.The comparison between the lateral displacement calculation results of the retaining wall and the calculated values of the technical specifications shows that the lateral displacement value of the retaining structure calculated by the HS-Small model is smaller than the calculated value of the technical specifications,and the difference value is larger where the support is weak.

关 键 词：HS-Small模型 数值分析 基坑 软土 

分 类 号：TU753[建筑科学—建筑技术科学]