Comparison between Seismic Performance of Semi-Integrated Bridge and Conventional Bridge

The performance of a three-span integrated bridge is evaluated and compared with a conventional bridge for unidirectional and bi-directional excitation. The conventional bridge deck is connected to abutment through elastomers and the pinned connection is assumed at pier location. The height of the piers is 9.5 m, and the central and end spans are 38.0 m and 15.5 m respectively. A nonlinear time history analysis of the bridge is performed by using CSI Bridge software, for unidirectional and bi-directional excitation. The responses of the integrated bridge are compared with those of the conventional bridge in which bearings are provided between the deck and the support. The parameters varied are the major direction of the application of earthquake time history and PGA. The response quantities of interest include the maximum base shear of piers, maximum stresses developed at the critical sections of the deck, maximum deck deflection at the mid-span, and at the pier supports. The results of the numerical study show that as compared to the conventional bridge the integrated bridge has less base shear but has more stresses in the deck near pier supports; however, the stresses developed at the mid-span of the deck are significantly reduced.