Resolution of Site Response Issues from the Northridge Earthquake

9529159阿基该项目汇集了来自多个组织的地质学家、岩土工程师和地震学家的强有力的协调小组，以解决北岭地震引起的岩土工程场地特征和地面运动响应问题。 拟议的工作在很大程度上是由加州交通部分摊费用，电力研究所、南加州地震中心和美国地质调查局分摊额外费用，并与加州矿业和地质部合作。 该项目的目标是：1）收集、汇编和迅速向研究界传播高质量的场地岩土和地球物理数据; 2）集中分析以下内容：* 确定当地场地和区域波传播效应对强地面运动的控制程度，包括非线性场地反应;* 评估传统估计地盘影响的方法是否足够，方法包括：量度所得的剪切波速、实验室测试结果，以及一维等效线性及非线性分析;* 评估模型的复杂程度（2-D和3-D分析）需要充分解释场地效应;确定测量特性的不确定性以及这些不确定性如何影响地面运动预测。 研究目标分三个阶段由地质学家、地震学家和岩土工程师组成的综合小组完成。 通过一个正式的咨询结构，促进了各机构之间的广泛协调。 在第一阶段，在有强烈运动记录和/或结构故障的重要地点进行一系列岩土工程调查。 在第二阶段，评估第一阶段收集的数据，并与其他数据收集工作的结果相结合，建立一个全面的数据库，模拟地面运动。 目的是 建立包括材料应变相关性的标准一维岩土模型以及二维和三维结构模型。 讲习班将促进调查人员之间的协调和数据的传播。 第3阶段包括对第2阶段收集的数据进行现场响应分析，并将地面运动响应计算结果与北岭地震观测结果进行比较。 最终报告将记录现场调查和现场反应问题以及所有进行的地面运动分析。 ***

9529159 Aki This project brings together a strongly coordinated group of geologists, geotechnical engineers and seismologists from a number of organizations to address geotechnical site characterization and ground motion response issues resulting from the Northridge earthquake. The proposed work is heavily leveraged by cost-sharing from the California Department of Transportation, with additional cost-sharing from the Electric Power Research Institute, the Southern California Earthquake Center, and the U.S. Geological Survey, and with cooperation from the California Department of Mines and Geology. The objectives of the project are: 1) collection, compilation, and rapid dissemination of high- quality site geotechnical and geophysical data to the research community; and 2) focused analyses limited to the following: * determining the extent to which local site and regional wave propagation effects control strong ground motion, including nonlinear site response; * evaluating the adequacy of the conventional approach to estimating site effects using: measured shear-wave velocities, the results of laboratory tests, and one-dimensional equivalent- linear and nonlinear analyses; * assessing the degree of model complexity (2- and 3-D analyses) required to adequately explain site effects; and * determining the uncertainties in measured properties and how these uncertainties affect ground motion predictions. The research objectives are addressed in three phases by the integrated group of geologists, seismologists and geotechnical engineers. Extensive coordination between institutions is facilitated through a formal advisory structure. In Phase 1, a series of geotechnical investigations are conducted at significant sites of strong motion recordings and/or structural failures. In Phase 2, data collected in Phase 1 is evaluated and combined with results of other data collection efforts to establish a comprehensive database for modeling ground motion. The aim is to establish standard 1-D geotechnical models that include material strain dependencies, as well as 2- and 3-D structural models. A workshop will facilitate coordination between investigators and dissemination of data. Phase 3 involves site response analyses of the data collected in Phase 2, with comparisons made of ground motion response calculations to Northridge earthquake observations. The final report will document site investigations and site response issues as well as all of the ground motion analyses conducted. ***