基于三维非连续几何模型的盾构施工模拟

以苏州地铁一号线工程为研究背景,建立考虑管片分块、连接螺栓及施工过程各因素的三维非连续几何模型,对盾构法施工过程进行仿真模拟.论述了盾构开挖系统模型的几何非线性方程组的推导过程,盾构顶进推力及注浆材料性质的计算方法.模拟计算结果显示：盾构管片内外侧表面大部分区域处于受压状态,拱顶与拱底部位及靠近连接螺栓的部分区域处于受拉状态;受盾构顶推力作用,盾构开挖面前方土体有一个典型的隆起区域,地表最大隆起值为2.5 mm,出现在盾构开挖面前方8.5 m处;盾构开挖面后方土体沿隧道纵向的沉降受注浆材料影响随时间变化,并逐渐趋于稳定;在盾构法施工中,各管片连接处的土体受施工影响明显,土体塑性区范围较大.

Simulation of shield tunnel construction process base on 3D discontinuous geometry model

Abstract：Based on the 1 g metro line of Suzhou, a 3D discontinuous geometry model about segment blocks, connecting bolts and construction process factors was built to simulate the construction process. It mainly intro- duces the derivation process of geometry nonlinear equations of shield tunnel excavation model, and the calcula- tion method of shidd thrust force and grouting material properties. The simulate results show that, nac~t of the area on the inside and outside surface of shield segment am in compression, rome area on top and bottom posi- tion of tunnel are in tension, and the pesition near the cormecting bolt are also in tension. Because of shield jacking force, there is a typical uplift area ahead of shidd excavation face. The maximum uplift value on ground is 2.5 mm, and the distance between the maximum uplift section and shidd excavation face is 8.5 m. Due to grouting material properties change with time, the ground settlement curves along tunnel centerline which behind shield excavation face are ups and downs, but they finally tend to stabilize. During shidd tunnel construction process, the soil which near the segment joints is obviously affected by construction, so the soil plastic area is bigger than other positions.