Both 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, and 6. To apply the simplified analysis procedures to representative design and problems in order to validate their usefulness.
