【摘要】 以在汶川地震中遭到严重破坏的百花大桥为研究对象,结合其震害建立了考虑墩柱、系梁、板式橡胶支座、钢筋混凝土挡块、伸缩缝和桥台等构件非线性力学性能的数值模型,采用距桥址最近的卧龙台记录,使用增量动力分析法(IDA)对其进行分析,结果表明:18跨牛腿搭接长度偏小是直接导致5联发生整体倒塌的原因,而不合理的支座布置方式导致双柱式固定墩无法共同受力,使一侧桥墩过早发生严重损伤从而无法为主梁提供足够的纵向约束也是不可忽视因素。更多还原

【Abstract】 Baihua Bridge seriously damaged under Wenchuan earthquake was chosen as the study object. A numerical model was built considering nonlinear behaviors of columns,tie beams,laminated rubber bearings,reinforced concrete transverse retainers,expansion joints and abutments. Then,an incremental dynamic analysis( IDA) was performed with ground motions recorded at Wolong station,the nearest station from the bridge. The numerical analysis results showed that the collapse of the fifth continuous girder is mainly caused by the smaller bearing length at the eighteenth span; the unreasonable support distribution manner is another significant factor to lead to two columns of the fixed pier cannot bear load together; thus,the fixed pier can not offer enough vertical restraint to the girder because one of its columns is damaged severely very early.更多还原