高速列车作用下简支梁的动力响应分析

Dynamic Responses Analysis of Simple Supported Beam Under High Speed Train

武广客运专线是我国目前建设的线路里程最长、技术标准最高、投资规模最大的铁路客运专线,采用上部大型建筑与下部桥梁共同组成的"桥建合一"新型结构,该新型结构动力性能和结构稳定分析难度大。基于移动荷载作用下简支梁动力响应计算的基本理论,采用ANSYS大型通用软件建立了移动荷载列-桥梁的数值计算模型,其中将列车荷载简化为移动的荷载列。计算了桥梁的自振频率、变形及加速度等动力响应,得到了桥梁支座处的反力时程曲线及其富氏谱,同时分析了桥梁盆式橡胶支座橡胶块弹性性能对桥梁动力响应的影响。计算结果表明在限定的车速下,桥梁不会发生共振,且桥梁的频率、变形及加速度等各项技术指标均满足相关规定,表明桥梁的动力设计是合理的。

The special passenger railway from Wuhan to Guangzhou is the longest special passenger railway in China,and also with the features of the highest technical standards and the largest investment scales.The station adopts the structural form of combination of bridge and building,which is difficult to analyze its dynamic behavior and structural stability.Numerical calculation model for moving loads and bridge is established by the software ANSYS based on the basic theory of dynamic response of simple supported beam under moving loads,in which the high-speed train is modeled by a series of moving loads.The frequency and deformation and acceleration of bridge are calculated.The time history and Fourier spectrum of reaction forces at the bearing are obtained.Then,the influence of elastic property of rubber block in basin rubber support to the dynamic response of bridge is analyzed.It is shown from calculation results that resonance will not be occurred and the technical indexes such as frequency and deformation and acceleration of the bridge all satisfy the relevant regulations,which indicates that the dynamic design of the bridge is rational.