汶川地震百花大桥震害分析

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。

Seismic Damage Analysis of Baihua Bridge in Wenchuan Earthquake

Baihua Bridge, which was seriously damaged in Wenchuan earthquake, was chosen as the object of study. A numerical model was created, in which the nonlinear behaviors of columns, tie beams, laminated rubber bearings, reinforced concrete transverse retainers, expansion joints and abutments were considered. Then a Incremental Dynamic Analysis (IDA) was carried out with ground motions recorded at Wolong station, which is the nearest station from bridge. The results of numerical analysis showed that the collapse of the fifth continuous girder was mainly caused by the small bearing length at the eighteenth span. And the unreasonable support distribution method was another significant factor, which lead to two columns of the fixed pier cannot bear load together. Thus the fixed pier could not offer enough vertical restraint to the girder because one of its columns was damaged severely very early.