A U.S. Japan Cooperative Study on the Effects of Near-Field Ground Motions

美国和日本都面临着类似的严重地震危险，包括近场事件的威胁。北岭和科比地震清楚地证明了这一点。 目前，两国正在根据地震中的实测数据和观测到的结构性能，重新审视各自的设计和分析方法，并朝着新一代的“基于性能”的结构设计和分析方法迈进。本项目的目的是对近场地震动及其对结构设计的影响进行美日一体化研究。 该研究的重点是发展和评估的简化方法来描述结构系统的性能。 本研究旨在解决在早期研究中发现的一些重要问题。 这也是为了帮助美国和日本考虑近场效应的基于性能的工程方法提供更坚实的基础。分析美国和日本的近场加速度记录，以确定结构分析和设计中需要考虑的最重要的特性。为了检验可用于近场地震地面运动的各种类型的需求谱，3。对一组具有不同滞回特性的理想结构模型在各种近场地震动作用下的反应进行参数研究。为了获得对近场地震动作用下结构系统非弹性反应本质的基本认识，5.适当地，为承受近场地面运动的结构制定简化的分析程序;将简化的分析程序应用于有代表性的设计和问题，以验证其有效性。

9812522IwanBoth the U.S. and Japan face similar serious earthquake hazards including the threat of near field events. This has been clearly demonstrated by the Northridge and Kobe earthquakes. Both countries are currently re-examining their design and analysis methodologies in light of the measured data and observed structural performance in these earthquakes, while moving toward a new generation of "performance-based" methodologies for structural design and analysis.The purpose of this project is to conduct an integrated U.S. Japan study of near-field ground motions and their implications for structural design. The research is focused on the development and evaluation of simplified methods for describing the performance of structural systems. This study is intended to resolve a number of important issues that have been identified in earlier studies. It is also intended to help provide a firmer basis for performance-based engineering approaches in the U.S. and Japan considering near-field effects.The specific objectives of the research are:1. To analyze a selection of near-field accelerograms form the U.S. and Japan in order to determine the most important characteristics that need to be taken into account for structural analysis and design,2. To examine various types of demand spectra that may be used for near-field earthquake ground motions, 3. To perform parametric studies of the response of a set of idealized structural models with different hysteretic properties subjected to a variety of near-field ground motions,4. To gain fundamental insight into the nature of the inelastic response of structural systems subjected to near-field ground motions,5. To develop, as appropriate, simplified analysis procedures for structures subjected to near-field ground motions, and6. To apply the simplified analysis procedures to representative design and problems in order to validate their usefulness.