顶管同步顶进工作井稳定性三维数值分析

3D-FEM analysis on stability of shaft with conduit jacked synchronously in two directions

由于工期的需要,上海市西藏南路电力隧道工程#6工作井内两侧顶管需要同步顶进施工,运用大型非线性有限元分析软件对施工过程进行了三维弹塑性数值模拟,重点考虑了①两个方向顶管同步顶进时,后靠墙及工作井整体的稳定性;②使用顶管靠下面的4个油缸或全部6个油缸时,后靠墙产生的最大变形;③油缸顶力与后靠墙变形的关系;④后靠墙产生最大位移时,对油缸顶力合力方向的影响。计算结果表明设计方案是可行的,能够保证连续墙以及后靠结构的稳定,不会影响顶管顶进方向的精度。同时,计算结果也为方案的进一步优化提供了相关参数。

Because of the restriction of construction time, the method of two-direction jacking is employed in shaft N0,6 Power Tunnel Project of south Tibet Road in Shanghai, China. A nonlinear elasto-plastic simulation is carried out with three-dimension FEM program. The analysis emphasises on the following aspects： firstly, the stabilities of backup wall and slurry wall while two-direction jacking is running; secondly, the maximum displacement in X direction induced by four or six jack apparatuses; thirdly, the relationship between jacking force and displacement of backup wall; finally, the impaction to direction of resultant of jacking force while backup wall reaches to maximum displacement in X direction. The results indicate that the design scheme of the project is feasible. It can ensure the stability of the slurry wall and backup wall, and does not affect the precision of jacking direction. Moreover, the results provide relevant parameters for optimum design of the project.