基于三维有限元法的基坑角部效应分析

3-D FEM Analysis on the Corner Effect of Deep Excavation

矩形基坑的角部效应对其围护结构的变形有重要影响。通过三维有限元分析,确定了矩形基坑的临界长宽比,划分了基坑角部效应对基坑围护结构变形的影响区域,分析了不同空间尺寸基坑围护结构变形。研究表明:当基坑长宽比大于临界长宽比时,基坑围护结构位移的分布、作用在基坑围护结构上的土压力分布和坑底隆起量均不随长宽比的改变而改变,趋于某一定值,基坑的角部效应在一定范围内会较明显的限制维护结构的位移。

The corner effect has a significant effect on the deformation of the supporting system for the rectangular shaped deep excavation sites. The critical aspect ratio of the excavation site and the corner effect on the deformation influence zone are stud- ied by 3 dimensional finite element analyses. The deformations of various dimensions of supporting systems are also numerically analyzed. The results indicate when the aspect ratio of a rectangular excavation is greater than the critical aspect ratio, the de- formation distribution pattern, earth pressures on the supporting structures, and the magnitude of heaves at the bottom of the excavation, are approaching to the constant values and will not change with the variation of the aspect ratio. The corner effect limits the deformation of the supporting system.