Engineering applications of strong ground motion simulation
Engineering applications of strong ground motion simulation
复制标题
强地震动模拟的工程应用
DOI：
10.1016/0040-1951(93)90268-o
复制
发表时间：
1993
期刊：
影响因子：
2.9
通讯作者：
P. Somerville
中科院分区：
文献类型：
--
作者：
P. Somerville
本文介绍了一种用于工程实际的强地面运动模拟程序的编制、验证和应用。该程序使用经验源函数（来自近源强运动记录的小地震），以提供一个现实的代表性的影响，如源辐射，难以在高频率建模，由于其部分随机行为。波的传播效果建模使用简化的绿色的功能，旨在将经验源函数从他们的记录网站，在一个特定的网站在模拟中使用所需的。该程序已被验证对地壳和俯冲地震的强震记录。在验证过程中，我们选择了震源模型（包括断层滑动的空间非均匀分布）独立已知且具有丰富强震记录的地震，通过定量测量模拟和记录强震之间的拟合程度来估计模拟过程中的建模和随机不确定性。这种建模和随机不确定性是使用模拟程序得出的特定地点未来地震地面运动估计的总体不确定性的一部分。不确定性的另一个贡献是，由于未来地震的震源参数的不确定性，影响网站，这是估计从一套模拟产生的不同的源参数在其范围内的不确定性。在本文中，我们描述了验证模拟程序的地壳地震对强运动记录的1989年洛马普列塔，加州，地震，以及1985年墨西哥米却肯和智利瓦尔帕莱索地震的俯冲地震。然后，我们展示了应用程序的模拟过程中估计的设计反应谱的地壳地震在加州的电厂网站和俯冲地震在西雅图-波特兰地区的例子。我们还演示了使用模拟方法建模的强地面运动的衰减，并显示证据的影响，从下地壳的临界反射，导致观察到的扁平化的强地面运动的衰减从1988年萨格奈，魁北克，和1989年洛马普列塔地震。
The formulation, validation and application of a procedure for simulating strong ground motions for use in engineering practice are described. The procedure uses empirical source functions (derived from near-source strong motion recordings of small earthquakes) to provide a realistic representation of effects such as source radiation that are difficult to model at high frequencies due to their partly stochastic behavior. Wave propagation effects are modeled using simplified Green's functions that are designed to transfer empirical source functions from their recording sites to those required for use in simulations at a specific site. The procedure has been validated against strong motion recordings of both crustal and subduction earthquakes. For the validation process we choose earthquakes whose source models (including a spatially heterogeneous distribution of the slip of the fault) are independently known and which have abundant strong motion recordings.A quantitative measurement of the fit between the simulated and recorded motion in this validation process is used to estimate the modeling and random uncertainty associated with the simulation procedure. This modeling and random uncertainty is one part of the overall uncertainty in estimates of ground motions of future earthquakes at a specific site derived using the simulation procedure. The other contribution to uncertainty is that due to uncertainty in the source parameters of future earthquakes that affect the site, which is estimated from a suite of simulations generated by varying the source parameters over their ranges of uncertainty.In this paper, we describe the validation of the simulation procedure for crustal earthquakes against strong motion recordings of the 1989 Loma Prieta, California, earthquake, and for subduction earthquakes against the 1985 Michoacán, Mexico, and Valparaiso, Chile, earthquakes. We then show examples of the application of the simulation procedure to the estimatation of the design response spectra for crustal earthquakes at a power plant site in California and for subduction earthquakes in the Seattle-Portland region. We also demonstrate the use of simulation methods for modeling the attenuation of strong ground motion, and show evidence of the effect of critical reflections from the lower crust in causing the observed flattening of the attenuation of strong ground motion from the 1988 Saguenay, Quebec, and 1989 Loma Prieta earthquakes.