Seismic Performance of Structures with Multi-Plastic Hinge subjected to an extreme earthquake ground motion

点击翻译按钮获取中文摘要

In the current seismic design procedure for structures with multi-plastic hinge, only a dominant plastic hinge is considered and secondary plastic hinges were disregarded because the interaction of nonlinear behavior between the dominant plastic hinge and secondary plastic hinges has not yet be clarified from the point of system nonlinear response.The yield strength ratio between dominant plastic hinge and secondary plastic hinge is one of sensitive parameters in the nonlinear interaction between the dominant plastic hinge and secondary plastic hinges. Therefore for two plastic hinge structures such as an isolator-column of bridge system and a bridge-column-pile foundation system, the dependence of the yield strength ratio on the hysteretic energy dissipation is clarified from a series of nonlinear dynamic response analysis.In order to clarify the mechanism to form the secondary plastic hinges after a dominant plastic hinge was formed, the push over analysis for a bridge-column-pile foundation system as well as a framed bridge was conducted. The loading path effect on deformation of structural elements and the multi-plastic process .was evaluated.This research project also conducted an analysis to predict exact nonlinear responses for structures with multi-plastic hinge. A multi-span continuous bridge supported by flexible elastomeric bearings was analyzed for such purpose that deformation of elastomeric bearings contributes to deck displacement, it was identified that the system ductility factor instead of the column ductility factor should be used to evaluate the force reduction factor.From the analysis, it became clear that the effect of multi-plastic hinge for system nonlinear response must be considered in the next generation codes of seismic design.