城市高架桥中大跨度钢箱梁桥往往与小跨度混凝土梁桥相接,两者间存在较大的刚度和质量差异,将表现出不同的静力和动力特性。以某立交桥为工程背景,用MIDAS/CIVIL建立采用高阻尼隔震橡胶支座(HDR)的不同上部结构形式曲线箱梁桥的有限元模型,通过计算结构在静载及动载下的受力性能,探讨HDR在曲线箱梁桥中的适用性。研究结果表明:由于HDR约束刚度相对盆式支座较小,间接荷载作用下桥墩横桥向弯矩也较小;直接荷载作用下,盆式支座有利于荷载在桥墩之间的分配和传递,使单个桥墩内力减小。HDR对结构变形的控制相对较弱,当两联结构差异较大时,应注意联间径向位移差的控制。采用HDR后,本桥纵向减震率在20%-60%之间,横向减震率在60%-80%之间,达到良好的减隔震效果。
Long span steel box girder is usually connected with small span concrete box girder in urban viaduct,but there are large differences in static and dynamic characteristics between them because of the difference in ri-gidity and mass. Based on an overpass bridge, finite element models of curved girder bridge with different param-eters of High Damping Rubber (HDR) bearing were established by Midas/civil. The applicability of High Damp-ing Rubber bearing in curved box girder was discussed by calculating the structural mechanical behavior understatic and dynamic loads. The calculation results show that the transverse moment in pier bottom is smaller underindirect loads because the restraint stiffness of HDR bearing is smaller than pot-type elastomeric pad bearing,but the internal force of piers under direct loads is smaller because the pot-type elastomeric pad bearing is suit-able for transferring load. The radial displacement between different bridges should be checked if the structuresare very different, because HDR bearing can/t control the transverse displacement effectively relative to pot-typeelastomeric pad bearing. With HDR bearing, isolation efficiency of this bridge is from 20% to 60% in longitudi-nal direction, from 60% to 80% in transverse direction.