An Approximate Expression of Slip Velocity Time Function for Simulation of Near-field Strong Ground Motion
An Approximate Expression of Slip Velocity Time Function for Simulation of Near-field Strong Ground Motion
复制标题
近场强地震动模拟的滑移速度时间函数近似表达式
DOI：
10.4294/zisin1948.53.1_1
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发表时间：
2002
期刊：
影响因子：
--
通讯作者：
T. Miyatake
中科院分区：
文献类型：
--
作者：
Hiromitsu Nakamura;T. Miyatake
为了准确地模拟近场地面运动，必须采用物理上合理的断层滑动速度时间函数。虽然滑动速度的解析表达式更适合于模拟，但目前断层上的滑动速度是针对震源过程的每一组动力学参数进行数值估计的。在这项研究中，基于二维和三维裂纹模拟的数值解，包括滑移弱化摩擦定律，提出了滑移速度的近似表达式。对于滑移起始时间到最大滑移速度时间，滑移速度近似为基于具有滑移弱化摩擦定律的二维稳态裂纹解的二次函数。对于滑移历史的后半部分，基于滑移弱化摩擦律的交错网格有限差分方法对三维裂纹模拟结果进行了近似。描述滑移速度的重要参数是滑移速度的最大幅值、最大滑移速度的时间和上升时间。
In order to simulate near-field ground motions accurately, it is necessary to use a physically reasonable time function of the slip velocity on a fault. Although the analytical expression of slip velocity is preferred for the simulation, the slip velocity on a fault is currently estimated numerically for each set of dynamic parameters of source process. In this study, an approximate expression of slip velocity is proposed on the basis of the numerical solution of 2D and 3D crack simulations including a slip-weakening friction law. For the time of slip onset to the time of maximum slip velocity, the slip velocity is approximated by a quadratic function based on a solution of a 2D steady state crack with a slip-weakening friction law. For a latter part of the slip history, the slip velocity is approximated on the basis of results of 3D crack simulation using the staggered grid finite difference method with the slip-weakening friction law. The important parameters for describing the slip velocity are maximum amplitude of the slip velocity, the time of the maximum slip velocity, and the rise time.