强震作用下海底隧道多场耦合破坏机制研究

The artificial boundary conditions of energy radiation for layered finite field with saturated porous media considering fluid-solid coupling and fluid media are deduced. A hybrid integral method is proposed with finite difference and finite element method for fluid-solid coupling model. One dimension time domain method is studied for establishing model of free multi-phased field of layered half space, which includes the large ocean geological environments with fluid-solid coupling. The large model will be solved using parallel algorithm. According to the artificial boundary in time domain and corresponding condition of equivalent stress, a wave inputting method of spatially non-uniform seismic ground motion is proposed based on multi-scale method. A time domain model of nonlinear dynamic interaction for whole ocean- geology-tunnel structure considering ocean, ocean body and earthquake waves, and oceans waves. A flume system is designed for flowing effecting of ocean water. A shaking table experiment for model of ocean- geology-tunnel structure under spatially non-uniform ground motion is developed based on three shaking table system. The numerical results are verified by the test. The failure mechanism of the ocean tunnel in saturated media is studied. The laws of wave propagation affected by local field effect including deep topography, different geology, depth of tunnel and depth of ocean are investigated. The deformation and failure behavior of the lining and the joint element are analyzed. The effective engineering measures are provided.

推导层状无限域流体介质和流-固耦合饱和多孔介质中能量辐射的人工边界条件，研究考虑多场耦合的成层半空间自由波场的一维时域化算法，求解考虑流-固多场耦合的大型海洋地质场的自由波场分析模型。研究流-固耦合的有限差分/有限元混合积分方法，根据研究的时域人工边界及相应的应力等效条件，基于多尺度方法提出考虑地震动空间非一致性的地震输入方法，建立考虑地震波、波浪和海流的海水－海洋工程地质体－海底隧道结构的非线性动力相互作用的整体时域模型。基于地震模拟振动台三台阵系统，设计流动水槽模拟近似稳流海洋水流效应，开展海水－海洋工程地质体－海底隧道系统地震动非一致性的模拟试验，对数值模型进行验证。结合并行算法进行饱水介质中海底隧道失效破坏过程及其模拟研究，研究海沟地形、地质、埋深及海水等场地局部场地效应对地震波传播规律的影响；分析海底隧道衬砌构件和连接件的动力变形特性及失效破坏特征，提出有效的抗震措施。

推导了层状无限域流体介质和流-固耦合饱和多孔介质中能量辐射的人工边界条件，基于 biot 饱和土介质动力方程的 u-p 形式研究了反映饱和土无约束域能量辐射效应影响的等效黏弹性人工边界单元，基于地震波转化为作用于人工边界节点上等效荷载的方法实现了波动输入。采用算例验证了等效人工单元的精度。研究了考虑多场耦合的成层半空间自由波场的一维时域化算法，采用有限差分方法，推导建立了SH波斜入射情形下、考虑土体介质阻尼影响的水平成层弹性介质出平面自由波场求解的显式数值逐步法公式，并采用Matlab程序语言编制了相应的数值计算程序。根据研究的时域人工边界及相应的应力等效条件，基于多尺度方法提出考虑地震动空间非一致性的地震输入方法，建立了考虑地震波、波浪和海流的海水－海洋工程地质体－结构的非线性动力相互作用的整体时域模型。基于地震模拟振动台三台阵系统，开展了海水－海洋工程地质体－海底隧道系统地震动非一致性的模拟试验，对数值模型进行验证。结合并行算法进行饱水介质中海底隧道失效破坏过程及其模拟研究，研究海沟地形、地质、埋深及海水等场地局部场地效应对地震波传播规律的影响。