盾构机掘进对大堤安全影响的三维数值模拟及试验验证

基于自适应接触算法,建立盾构机、土体、大堤三者相互作用三维非线性有限元模型,结合刚度迁移法对盾构机掘进过程进行仿真,详细模拟盾构机超挖、机身坡度、机身与土体的相互作用、注浆时空变化性质、开挖面泥水压力、拖车作用等施工因素.模拟结果在与试验段实测数据进行对比的基础上,预测了大堤在盾构机掘进过程中的沉降规律,为越江隧道施工过程中保障防洪大堤的安全提供参考.

Impact Analysis of Tunneling Process on Flood Levee by Three Dimensional Numerical Simulation with Verification by Test Section

Based on adaptive contact algorithm, a three dimensional nonlinear FEM model was established with important interaction effects between shield tunneling process, soil, and the flood levee. The moving-forward shield tunneling process was simulated by stiffness transferring method. All relevant component of construction process (the over-cut of shield machine, the taper of shield skin, the contact between shield skin and soil, the time dependence of the grout material characteristics, the slurry pressure at the excavation face, the loading of back up trailer) were taken into account. The simulation results were validated by comparison with field measurements from test section. The predicted settlements of flood levee during shield tunneling process can provide a reference for insuring the safety of flood levee.