大跨径钢管混凝土拱桥减震控制装置参数的研究

大跨度桥梁结构的减震控制研究对于桥梁结构的抗震安全具有重要意义。本文以主跨368m的茅草街大桥为研究对象,基于ANSYS建立了该桥的三维有限元模型,并采用子空间迭代法分析了该桥的动力特性。在此基础上进行了大跨度钢管混凝土拱桥的地震响应及减震控制研究,重点进行了弹性连接装置和粘滞阻尼器减震效果的参数敏感性分析,并对比分析了不同位置布设减震装置时的效果。结果表明,纵飘振型对该桥肋纵向相对位移的贡献最大;弹性连接装置和阻尼器均能有效减小地震作用下该桥的肋梁纵向相对位移;综合考虑各关键部位的地震响应时,同时采用两类减震装置并将其分散布置时的减震效果最佳。结论可供大跨度中承式钢管混凝土系杆拱桥的抗震设计参考。

Parametric Study on Seismic Control Device of Long-span Concrete-filled Steel Tubular Arch Bridge

Research on the seismic response control of long-span bridge is of great significance for bridge seismic safety.In this paper,Maochaojie Bridge with a main span of 368m is taken as an example.A 3-dimensional finite element model of the concrete-filled steel tubular（CFST） bridge is established based on ANSYS and the modal analysis is conducted by using the subspace iteration method. The seismic response and control of long-span CFST arch bridge are investigated.The parametric sensitivity study on seismic control devices including the elastic connection and the viscous dampers are emphasized.Moreover,the control effects of devices installed at different locations are compared with each other.Results show that the longitudinal mode shape makes the greatest contribution to the longitudinal relative displacement between girder and arch ribs;both the elastic connection devices and the dampers can effectively reduce the relative displacement between girder and arch bids;when all of the seismic responses of key sections are considered,using the elastic connection and the dampers together and installing the devices evenly can achieve the optimal control effect.The conclusions can provide references for the seismic design of long-span half-through CFST arch bridges.