【摘要】 基于改进后的土体离散-连续耦合算法,对坂神地震中神户大开地铁车站的坍塌破坏过程进行了数值模拟.通过改进适用于Lagrange乘子法求解的优化模型,来强化离散和连续模型在耦合边界上力的相容性,并将改进后的算法嵌入离散-连续耦合动力模型.在耦合边界通过交换速度和力保证耦合模型的连续性,通过自振柱模拟和循环双轴模拟使离散区域土体的宏观动力属性与连续土体模型一致.土体离散-连续耦合方法可以从细观尺度描述重点考察区域土体和结构的破坏过程,并有效降低离散元的模拟规模.模拟得到的车站破坏形式与文献中现场情况非常接近,并从定量角度与文献中基于连续体的模拟结果进行了比较.更多还原

【Abstract】 Based on the improved discrete-continuum soil model,the collapse process of the Daikai station is computationally modeled.The improved optimization model via the Lagrange multiplier method is employed.The continuity between the discrete and continuum domains is fulfilled by interchanging velocities and forces between them.By performing the free vibration column simulation and numerical cyclic biaxial tests,the degradation curve of the particle assembly is obtained and then applied to the continuum model.Results show that computationally obtained damage pattern is similar to the real collapsed situation of the subway station after the earthquake.Besides,the computationally obtained horizontal differential displacement of subway station column is in qualitative agreement with the existing published results.The present coupled macro-micro approach not only can efficiently reduce particle numbers but also provide a microscopic damage details within the concerned zone.更多还原