大跨度拱桥弹性动力失稳的简化计算

Simplified Method for Evaluating the Elastic Dynamic Instability of the Long Span Arch Bridge

基于Liapunov动力稳定性意义,针对拱结构弹性失稳的特点,研究改进了需对结构整个振动时间历程进行特征值抽取的动态特征值法,通过引入静力稳定系数以及结合关键构件的线性时程计算结果,提出简化的计算方法确定拱桥的动力失稳临界荷载,并以一座实际大跨度拱桥为例进行计算验证,结果表明:该简化方法具有概念清晰,计算快速、准确的特点,可以为大跨度拱桥的动力稳定性能研究提供更为有效的研究手段,同时也适用于其他存在稳定问题的土木工程结构。

Based on the sense of Liapunov dynamic stability and the features of elastic buckling of arch bridge, and using the static buckling eigenvalue as well as linear time history analysis result, a simplified method for evaluating the elastic dynamic instability was developed from the so called ＂dynamic eigenvalue method＂ that needs to extract the minimum buckling excitation. The presented method was compared and eigenvalues step by step under the whole earthquake validated to be efficient and accurate via a case study, and therefore it could be used as a more effective method to study the dynamic stability issue of long span arch bridges and other civil engineering structures.