INVESTIGATION OF THE EFFECT OF THE GROUND MOTION CHARACTERISTICS ON THE Ry-u RELATION FOR THE INELASTIC RESPONSE OF SDOF STRUCTURES
In this study, the effect of the ground motion frequency content, especially the period of the directivity pulse in near field records, on the relationship between the reduction factor Ry and the ductility demandu is investigated. A large sample of strong motion records showing near field characteristics of forward and backward directivity,is examined. The regimes, in which the known assumptions of equal displacement and equal energy are valid, are re-evaluated taking into account the period of the directivity pulse contained in the ground motion. The results show that, for near field records with directivity effects, the thresholds of these regions depend on the period of the directivity pulse, which is related to the magnitude of the earthquake. This observation is valid for ground motions with intense and weak forward directivity and backward directivity effects. This response structures with a period larger than Tc, with Tc being the threshold between the constant acceleration and the constant velocity regions on the response spectrum, might underestimate significantly the ductility demand for structures with long periods. In this analysis, a new method for deriving the pulse duration in case of weak forward and for backward directivities is proposed and a new limit for the regime, in which the equal displacement assumption applies, is defined.
Near field ductility inelastic response reduction factor behaviour factor.
I. Taflampas I.N. Psycharis
Civil Engineer, Laboratory for Earthquake Engineering , National Technical University of Athens, Gre Assoc. Professor, School of Civil Engineering, National Technical University of Athens, Greece
国际会议
14th World Conference on Earthquake Engineering(第十四届国际地震工程会议)
北京
英文
2008-10-12（万方平台首次上网日期，不代表论文的发表时间）