大跨度连续梁桥摩擦摆支座布置及参数研究

以1座(71+83+123.5+240+123.5+83+71)m大跨度连续梁桥作为研究对象,研究摩擦摆支座的布置方式以及支座的力学参数取值对结构的地震响应的影响。分析结果表明:采用摩擦摆隔震支座体系的大跨度连续梁,在E2地震作用下,能大幅降低原固定墩的受力,使得各墩内力分布更加均匀,同时降低墩顶的位移;综合考虑可以仅在主跨的主墩上布置摩擦摆支座;摩擦摆支座摩擦系数的变化对结构地震反应影响很大,摩擦系数的增大虽然使支座耗能能力增加,但是过大的摩擦力不能有效地阻断墩梁间惯性力的传递,不能充分发挥隔震支座的耗能作用,建议摩擦系数采用0.02~0.03;摩擦摆支座半径的变化对结构地震反应影响很小,建议根据支座竖向承载力采用相应的曲率半径。

Study on Friction Pendulum Bearing Arrangement and Parameters for Long-span Continuous Girder Bridge

Taking a long-span continuous girder bridge with spans of( 71 +83 +123. 5 +240 +123. 5 +83 +71) m as the research objective,this paper studies the influence of arrangement friction pendulum bearings arrangement and bearing mechanical parameters on the seismic response of the structure. The results show that the long-span continuous girder bridge with friction pendulum bearing can significantly reduce the stress of the original fixed piers with pier stress distribution more uniform,while reducing the displacement of pier top under the E2 earthquake; the friction pendulum bearing may be arranged only on the main pier of the main span; the changes of the friction coefficient of friction pendulum bearings pose great influence on seismic response of structure,so that the increase of friction coefficient results in bigger bearing energy consumption,but excessive friction fails to effectively block the transmission of inertia force between pier and girder,and give full play to the role of energy isolation bearings. Thus,we recommend 0. 02 to 0. 03 of friction coefficient. As the changes in radius of friction pendulum bearings have little effect on seismic response of structure,corresponding radius of curvature is employed according to the vertical bearing capacity.