倒挂井壁法竖井衬砌结构受力分析

Analysis on Lining Structure Stress of Shaft by Top-down Wall Method

以贵阳市轨道交通车站竖井衬砌结构设计为背景,分别建立平面应变模型和三维梁-壳单元模型,分析竖井衬砌在不同围岩应力场下的内力。研究表明:平面应变模型计算简便,但未能考虑围岩应力随深度的变化和竖井结构的空间效应,这与平面问题的假设不符;三维梁-壳单元能较为准确地反映竖井衬砌结构内力随深度的变化,结构设计时可根据竖井衬砌的内力分段优化钢架的间距;竖井衬砌侧压力应收集更多的现场实测数据,与理论计算值进行对比分析,以优化竖井结构设计。

Taking the design of shaft lining structure for the rail transit station of Guiyang as the background,the plane strain model and the 3 D beam-shell element model are established respectively to analyze the internal forces of shaft lining in the different stress fields of surrounding rock. The results show that plane strain model has the characters of simple calculation, but cannot consider the variation of rock stress with depth and the space effect of shaft structure, which is incompatible with the assumption of a plane problem. 3 D beam-shell element model can more accurately reflect the variation of the internal force of the shaft lining structure with depth. The spacing of steel frames can be optimized by segments according to the internal force of shaft lining in structural design. More field measured data of lateral pressure on shaft lining is needed.Compared with the theoretical calculated data, the structural design of shaft is optimized.