活动支座摩擦力对连续梁桥抗震性能的影响

Effect of sliding bearing friction to seismic performance of continuous beam bridges

为揭示连续桥梁支座摩擦作用在地震波作用下的响应规律,采用动态时程分析法,以预应力混凝土现浇连续箱梁桥为背景,建立三种工况的有限元模型,借助ANSYS有限元软件分析了El-Centro波、天津波对支座、桩径、初始刚度等多种工况下的减震率影响的变化规律,得出了对于连续桥梁设置活动支座有利于桥梁抗震,认为在桥梁抗震中由固定墩单独抗震设计是偏于安全的.研究表明,对于连续桥梁在进行抗震设计时应考虑活动支座的摩擦作用,最佳摩擦系数的确定应考虑到桥梁结构刚度、模型简化体系的影响.

In order to reveal the respond rules of the continuous bridge bearing friction action in seismic waves,using dynamic time history analysis,against the background of cast-in-situ prestressed concrete continuous box girder bridge,the finite element model in three working conditions is built.With the finite element software—ANSYS,this study analyzed the change rules of El-Centro waves and Tianjin seismic waves effections of vibration decreasing ratio on bearing,stake diameter and initial stiffness in several working conditions.The setting expansion bearing on continuous bridge is conducive to shock resistance,and separate seismic design for the anchor block in the bridge anti-earthquake is in favor of safety.The result of research shows that seismic design for continuous bridge should consider the frictional effect of expansion bearing,and the determination of the best friction coefficient should consider the influence of bridge structure stiffness and model simplified system.