类矩形盾构施工中的SPH流体动力学应用探索

Explorative Research on SPH Fluid Dynamics Applied in Quasi-Rectangular Shield Construction

切削改良排土和盾尾同步注浆是盾构隧道掘进中与地层直接交互且不可见的2个施工环节,其相对其他内部可见工序具有更大的不确定性和风险性,且这类施工步骤中控制参数的选取决定着盾构对周围环境的影响程度。当前,较多基于网格的方法已经广泛地应用在盾构施工的各种静态、准静态或动态模拟中,但其固有缺陷阻碍了数值分析的进一步精细化研究。文章结合国内首个类矩形盾构隧道工程实例,引入一种无网格方法——光滑粒子流体动力学(SPH)来分析盾构施工中改良土体和浆液材料对象的极大变形特征及其施工动态效应,通过数值方法对比、运动机理分析以及部分算法的针对性改进,对这两种工艺中流(塑)体的大变形实时仿真和细观分析进行了创新性的应用探索,得到了部分具有指导性的结论和建议。

Improved soil cutting and shield tail synchronous grouting are two invisible procedures interacting directly with the strata during the shield tunnelling,which has more uncertainties and risks compared with other visible procedures and selection of its control parameters may directly relate to environment influence caused by shield construction.Considering that many grid based methods applied widely in various static,quasi-static and dynamic simulations of shield tunnelling hinder the further fine research of numerical analysis due to their inherent defects,and a SPH(Smoothed Particle Hydrodynamics) fluid dynamics method is proposed based on the first case of quasirectangular shield tunnelling to analyze the large deformation characteristics and dynamic effects of improved soil and grout material during shield construction,a creative exploration for the real-time simulation and microstructure analysis of large deformation is carried out through numerical contrast,kinetic mechanism analysis and targeted improvement of some algorithms.