盾构法隧道施工的精细模拟

Elaborate Simulation of shield tunneling

在分析了现有的部分细节仿真中存在问题基础上,提出在盾构开挖面前方设置开挖卸荷单元,来模拟开挖面土体的三维移动,改进了千斤顶推力的施加方法。通过施加已知结点位移模拟刀盘超挖和盾尾脱空引起的地层损失,并通过设置横向和纵向三维 Goodman 接触面来模拟盾构前行、盾尾脱空及注浆作用下土体与结构间的接触。利用推荐的方法对一算例进行分析。结果证明了模拟方法的合理性。

An unloading element is introduced to model the three-dimensional displacement of soil at tunnel face; the applying method of jack force behind the machine is modified, the ground loss caused by over excavation and tail void was simulated by adding known node displacements;transverse and longitudinal interface element was placed to simulate the soil-structure contact during the machine driven forward, filling of tail void and grouting. The proposed modeling techniques of shield tunneling construction are applied to simulate a tunneling project; the displacement of soil caused by shield tunneling are investigated; and the results prove the rationality of the proposed simulation method.