学术论文详情

摘要：A direct displacement based seismic design procedure of RC bridge piers fulfilled multiple performance objectives, which usually expressed as that designed structures can resist against minor earthquake without any damage, resist against moderate earthquake with repairable structural damage and resist against strong earthquake without collapse, is developed based on the improved capacity spectrum method. The procedure uses the yield displacement and displacement ductility factor as design parameters, uses inelastic seismic demand spectrum with yield spectral accelerations and yield displacements format to calculate seismic demands of the pier under different earthquake design levels. Seismic capacities of the pier are determined by acceptable structural damage states, which are estimated quantitatively by both of the strains of concrete and longitudinal steels in plastic hinge zone and expressed as displacements at top of the pier by transforming from relationship between curvature ductility factor and displacement ductility factor. Two specimens with 1:2.5scale are designed by the proposed method and another reference specimen with same scale is designed according to bridge seismic design code in China. The damage states, bearing capacities, ductility, and energy dissipation of specimens are compared when they are subjected to cyclic loading. Then four bridge specimens with 1:2 scale to the specimens in the completed cyclic test, 3 based on displacement-based seismic design method and 1 based on bridge seismic design code in China, are tested on shaking table. Results of cyclic test and shaking table test show that ductility capacities of bridge piers designed using displacement-based method are fulfilled seismic demands expected. The proposed displacement based seismic design method can be applied to the bridge design in the earthquake regions.