Evaluation of intensity measures for velocity pulse-like earthquake ground motions based on shear type MDOF systems

The correlation between intensity measures (IM) for velocity pulse-like earthquake ground motions and nonlinear deformation demand of shear type multi-degree-freedom (MDOF) systems is researched, and the efficiency of IM is described. Based on the nonlinear dynamic time analysis of MDOF systems subjected to 20 large velocity pulse-like ground motions, this work investigates the variation trend of the correlation coefficient between IM for pulse-like ground motions and maximum nonlinear roof drift demand of MDOF systems with the constant-ductility system setting. Linear regression and dispersion analyses are performed on these results to identify the efficiency of IM for pulse-like ground motions. The study shows that the fundamental period and ductility level of a structure have important influence on the correlation and dispersion. When PGV is used as IM for pulse-like ground motions, the correlation and dispersion is relatively stable with the large relative coefficient and the small dispersion.