ABSTRACT
Parametric studies on the dynamic response of a typical isolated bridge under three pulse-type ground motions were carried out in this study. The analysis results indicated that similar peak structural responses were induced under the three pulse motions. The peak isolator displacement could be effectively reduced as the stiffness ratio lied between 0.2 and 0.3. Seismic response of the isolated bridge under twenty pulse-like near-field and ten far-field earthquake records were compared with the pulse response. The analysis results indicated that for the considered range of the post-yield stiffness ratio, the mean-plus-one standard deviation response under the near-field seismic motions with scaled pulse period varied from 70% to 82% of that under the one-cycle Type-A pulse motions. Hence, the one-cycle Type-A pulse can be used as a pseudo-near field ground motion for the extreme seismic demand under pulse-like near-field earthquakes.
