Some continuous rigid frame bridges are constructed adjacent to active faults in western China, but the influence of the angle between the fault strike and the longitudinal bridge direction on the seismic response of rigid frame bridges is usually ignored in the seismic design. Four long span continuous rigid frame bridge models with different pier heights were established by Midas Civil software in this paper. Ten groups of near fault ground motions were selected for time history analysis to study the influence of the fault strike on seismic responses of the displacement and ending moments in rigid frame bridges. Results show that under horizontal bidirectional near fault ground motions, the longitudinal seismic response of main piers and main girders is the largest when the angle between the fault strike and the longitudinal bridge direction varies from 75° to 135°, while the maximum transverse seismic response occurs when the angle is in the ranges 0°-30° or 120°-180°. Compared with the seismic response of bridges under horizontal bidirectional ground motions, the vertical ground motion has a great influence on the vertical bending moment response of the main girder under three directional near fault ground motions. Specifically, the seismic response can be multiplied two or more times, especially at the junction of the main pier and the main girder of the rigid frame bridge. It is possible to underestimate the seismic response of the four bridges selected in this paper if analyzed without considering the angle between the fault strike and the longitudinal bridge direction; the underestimated error is about 15%-40%.
焦习龙,王荣霞,马海龙,王东升.断层走向对刚构桥地震反应的影响[J].地震工程学报,2023,(1):50-57. JIAO Xilong, WANG Rongxia, MA Hailong, WANG Dongsheng. Influence of fault strike on the seismic response of rigid frame bridges[J]. China Earthquake Engineering Journal,2023,(1):50-57.复制