温度对隔震简支梁桥梁体碰撞效应的影响

Impact of Temperature on the Collision Effect between Beams of Isolated Simply Supported Beam Bridge

为了探讨温度对隔震简支梁桥梁体碰撞效应产生的影响,以美国"AASHTO指导性隔震设计指南"为基础,结合国内铅芯隔震橡胶支座利用MIDAS软件对全桥建立简化的力学数值计算模型,并从PEER地震动数据库中选取具有代表性的5条地震波采用非线性时程法进行抗震分析,主要研究隔震简支梁桥在不同温度环境下梁体间的碰撞效应,研究结果表明:随着温度的降低,铅芯隔震橡胶支座刚度逐渐变大,致使梁体间的碰撞力随温度的降低也逐渐增大,强烈的碰撞易导致梁体的破坏及落梁事件的发生,因此,建议对位于低温环境下的隔震简支梁桥应选用耐寒性较强的隔震支座,以减小温度对梁体碰撞产生的不利影响,提高桥梁结构的整体抗震能力。

In order to investigate the impact of temperature on the collision effect between beams of isolated simply supported beam bridges,a simplified mechanical numerical model for the whole bridge is established with MIDAS in accordance with the United States guidelines for AASHTO guided isolation design and based on the lead rubber bearings in China. Five representative seismic waves are selected from the PEER ground motion database and nonlinear time history method is used for seismic analysis to study the pounding effect of isolated simply supported beam bridges under different temperature conditions. The results show that with the decrease of temperature,the stiffness of lead rubber bearings gradually increases,and the collision force between beams increases with the decrease of temperature,and strong collision tends to cause the destruction of the beam body and beam falling. Therefore,it is suggested that the cold shock isolation bearing should be used for isolated simply supported bridges in low temperature environment to reduce the adverse effect of the temperature on beam collision and improve the overall seismic capacity of the bridge structure.