饱和黏性土地基中邻近圆形基坑相互影响分析  

Analysis on the Interaction between Neighboring Circular Excavations in Saturated Cohesive Ground

作　　者：谢万东[1] 李建宇[1] 赖俊珊 Xie Wandong;Li Jianyu;Lai Junshan(CCCC-FHDI Engineering Co.,Ltd.,Guangzhou 510290,P.R.China)

机构地区：[1]中交第四航务工程勘察设计院有限公司,广州510290

出　　处：《地下空间与工程学报》2024年第S01期440-445,共6页Chinese Journal of Underground Space and Engineering

摘　　要：间距很小的圆形基坑后方土压力分布复杂,很难判断考虑圆拱效应的竖向弹性地基梁法和三维弹性地基板法的适用性。采用三维连续介质有限元法对位于饱和黏性土中2个间距很小的由地下连续墙组成的圆形事故应急池基坑进行整体建模分析。结果表明,对于1号池开挖到底后和2号池开挖到底后2种工况,地下连续墙的最大水平位移和最大弯矩的差异都不大。基坑位移和竖向弯矩的实测结果与计算值也较为接近。2个相邻圆形基坑在间距很小的情况下,其相互影响也是非常有限的。圆形地下连续墙支护结构对周围土体刚度参数的变化不敏感。采用三维连续介质有限元法对圆形地下连续墙支护结构进行计算分析,得到的结构内力远小于考虑圆拱效应的竖向弹性地基梁法和三维弹性地基板法,在经济性上有明显优势。The distribution of earth pressure behind circular excavations with small spacing is complicated,and it is difficult to determine the applicability of vertical elastic foundation beam method considering the arch effect and 3D spring slab method.The excavations of two circular accident emergency pools in saturated cohesive soil that are constructed by diaphragm wall with very small spacing are modelled by 3D continuum FEM method.The results show that the differences of maximum horizontal displacement and bending moment of diaphragm wall for the case of pool NO.1 excavated to the finial level and the case of pool NO.2 excavated to the final level are limited.The measured displacement and bending moment during construction deviate very little from the calculated values.The results indicated that even the spacing of two neighboring circular excavation is very small,the adverse interaction is very limited.Circular excavations retained by diaphragm wall is not sensitive to the stiffness of surrounding soil.The structural internal force of circular excavations calculated by 3D continuum FEM method is much smaller than that derived from vertical elastic foundation beam method considering the arch effect or 3D spring slab method,and obvious advantages in cost saving can be achieved.

关 键 词：圆形基坑 地下连续墙 饱和黏性土 三维连续介质有限元法 

分 类 号：TU473[建筑科学—结构工程]