基于MIDAS/GTS对悬臂式支护基坑空间效应的研究

RESEARCH OF SPATIAL EFFECT FOR EXCAVATION OF CANTILEVER RETAINING STRUCTURE BY MIDAS/GTS

利用MIDAS/GTS有限元软件对不同长宽比和不同开挖工况下悬臂式支护基坑的变形情况进行数值分析,结果表明当基坑长宽比L/B<2时,基坑长边全长都存在空间效应;当L/B>2时,距基坑角部大于1倍宽度区域内水平位移趋于稳定,其值和二维平面应变结果相近;距基坑坑壁小于1/2倍基坑宽度范围内坑底隆起量随距离增大而增大,大于1/2倍基坑宽度范围内坑底隆起量趋于稳定;基坑开挖深度对基坑空间效应的影响较显著,随开挖深度增加空间效应逐渐增强。

Based on numerical analysis by MIDAS/GTS, the influence of different aspect ratio and different excavation working condition on foundation pit deformation has been investigated. The results show that, When L/B is less than 2, entire long side of the foundation is effected by spatial effect. When L/B is greater than 2, there is no obvious different between 3D and 2D in the area from angle of the foundation pit more than double width, and the vale tends to stable. The bottom uplifts of excavation is enhanced with the increase of distance when the distance is less than the 1/2 width, and the bottom uplifts of excavation tends to a stable vale when the distance is greater than the 1/2 width. The depth of excavation is a significant element for spatial effect, and the spatial effect is enhanced with the increase of depth.