Spatial correlation of earthquake ground motion and spatial variability of geological characteristics in seismic hazard and risk assessment

在分布式组合和空间分布式系统（生命线）的地震损失估计中，平均预期损失和平均值附近的损失分布对决策和减灾活动非常重要。虽然平均损失是由单个损失的总和决定的，但损失的方差取决于地震地面运动的空间相关性。标准的灾害评估和标准的地震动预测不能处理相关性。从观测到的强震数据推导出地面运动的相关性质，只有在极少数地点才有可能，因为必须有非常高的数据密度。本项目的目的是通过引入一个将地震动的空间相关性与地质的空间变化联系起来的模型，发展地震地震动预测及其空间相关性的地震危险性和地震损失评估方法。具体项目有：1；利用日台数据库和现代地震动预报方程识别地震动空间相关因子利用传统地质统计技术和先进的copula方法分析土工地质特征的空间变异性2. 地震动空间相关参数与地质空间变异性特征定量关系的建立开发利用区域地质统计数据预测相关特性的模型；3. 在缺乏地面运动数据和相关结构信息的地区，展示了相关地面运动对危害评估、损失估计、地面运动建模和地震地图生成的相关性。该项目的创新之处在于：(1)我们不知道有任何系统的工作将地面运动的相关性与地质变化联系起来。(2)在保险和金融建模中广泛使用的copula也可能被证明是地震工程的有力工具。

In seismic loss estimation for distributed portfolios and spatially distributed systems (lifelines), the average expected loss and the distribution of loss around the mean are very important for decision making and mitigation activities. Whereas the mean loss is determined by the sum of individual losses, the variance of loss depends on the spatial correlation of earthquake ground motion. Standard hazard assessment and standard ground motion prediction cannot deal with correlation. Derivation of correlation properties of ground motion from observed strong motion data is only possible in very few locations as very high data density is mandatory. The objective of the project is the development of a methodology for earthquake ground motion prediction and its spatial correlation for seismic hazard and seismic loss assessment by introducing a model, which relates spatial correlation of ground motion with spatial variation of geology. Specific item are: 1. Identification of factors relevant for spatial correlation of ground motion using the databases accumulated in Japan and Taiwan and modern ground-motion prediction equations; analysis of spatial variability of geotechnical and geological characteristics using traditional geostatistical technique and advanced copula methods; 2. Establishing of quantitative relationships between parameters of spatial correlation of ground motion and characteristics of spatial variability of geology; development of model(s) that predict correlation properties from geostatistical data of regions; 3. Demonstration of relevance of correlated ground motion for hazard assessment, loss estimation, ground motion modeling and Shakemap generation in areas with a lack of ground motion data and information about correlation structure. The innovation by this project is twofold: (1) We do not know of any systematic work to link correlation of ground motion and variability of geology. (2) Copulas used widely in insurance and financial modeling may prove a powerful tool for earthquake engineering as well.