Seismic performance of simple-supported bridge subjected to pulse-type near-fault ground motions

Near-fault strong ground motions, which are characterized by large-amplitude long-period pulses, have resulted in the significant damage of structures. The reasonable analytical model for velocity pulse based on the existed models, which can be used to simplify the structural calculation, is developed. The velocity pulse model is defined by five parameters such as pulse period, pulse amplitude and number of significant pulses, etc. Based on the collecting large quantities of records of near-fault strong earthquakes, the parameters describing simplified model can be determined by a regression analysis. Time-history results of nonlinear dynamic analysis for the simple-supported bridge excited by representative pulse-type records and simplified pulses are used to demonstrate the validity of the proposed model to predicted the structural response. The calculation results noted that the propose model and its parameters can be used to reflect the seismic design of bridge structures.