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为了给地震高烈度区中小跨径连续梁桥的抗震设计提供设计参考,研究了桥墩与支座的不同组合形式对结构响应的影响。以某工程实例为背景,建立空间有限元分析模型,研究了桥墩与支座不同组合形式对结构自振特性的影响,在此基础上,利用弹性反应谱法、非线性时程法,对比分析了不同组合形式对结构地震响应的影响。研究结果表明,抗震设计时应控制桥墩设计刚度,矩形空心墩刚度较大,增大了支座和下部基础受力;综合考虑支座变形及抗滑性,高烈度区桥梁设计时不宜采用板式橡胶支座;采用盆式支座时,需考虑梁体与桥台的碰撞、落梁、高墩失稳等问题;采用墩顶固结时,主梁设计弯矩由地震作用下弯矩控制,增加了上部设计的复杂性;高烈度区中小跨径梁桥设计时,推荐采用圆柱墩配高阻尼橡胶支座的组合形式,该组合形式下结构抗震性能最佳。
In order to provide design reference for the seismic design of medium and small span continuous girder bridges with high seismic intensity, the influence of different combinations of pier and bearing on the structural response is studied. Based on an engineering example, a finite element analysis model is established to study the effect of different combinations of piers and supports on the natural vibration characteristics of the structure. Based on this, the elastic response spectrum method, nonlinear time history method, comparative analysis Influence of different combinations on seismic response of structures. The results show that the design stiffness of bridge piers should be controlled in seismic design, and the stiffness of rectangular hollow piers is larger, which increases the bearing capacity of foundation and lower foundation. Considering the bearing deformation and skid resistance, the bridge design in high intensity area should not adopt the plate Rubber bearing; When using the basin bearing, the problems of collision between the beam body and the bridge abutment, falling beam and instability of the high pier should be considered; when the pier top consolidation is adopted, the bending moment of the main beam is controlled by the bending moment under the action of earthquake , Which increases the complexity of the upper design. For the design of medium and small-span beam bridges in high-intensity zone, a combination of cylindrical piers and high-damping rubber bearings is recommended. The seismic performance of the structure under this combination is the best.