横系梁对双柱墩混凝土曲线梁桥地震反应的影响分析

Analysis of Cross Tie Beam on Seismic Reaction of Curved Concrete Bridge with Two-Columned Piers

为研究地震作用下,钢筋混凝土曲线梁桥中横系梁设置位置、刚度对结构受力的影响规律,以设置2道横系梁的双柱墩曲线梁桥为背景,考虑曲线梁桥的弯扭耦合效应和主梁间的非均匀碰撞效应,运用大型有限元软件ABAQUS建立桥梁的三维多尺度模型,设置6种横系梁位置工况,采用时程分析法分析不同位置横系梁对桥梁主梁、支座和桥墩的地震反应影响。最后,选择上述计算结果中较为合理的工况为背景,进一步研究横系梁刚度对桥梁地震反应的影响。研究结果表明:横系梁位置的变化对地震作用下曲线梁桥的主梁横向位移、支座受力、墩顶横向位移及墩底扭矩有比较明显的影响;横系梁沿墩柱较为均匀地分布时,对桥梁地震反应行为最为有利;适当地提高横系梁刚度可以减小桥梁的地震反应。

To study the influence of installation locations and stiffness of cross tie beams on the structural load bearing behavior of the reinforced concrete curved bridge under the action of earthquake, the curved beam bridge with two-columned piers and two cross tie beams is taken as the study background. Taking into consideration of the torsion-bending coupled effect of the curved beam bridge and the unbalanced collision effect between the main beams, the finite element soft- ware ABAQUS was used to establish the three-dimensional multi-scale models of the bridge. Six ways of cross tie beam installation were considered, and the time history method was used to ana- lyze the influence of seismic reaction of cross tie beams in different locations on the main beam, bearings and piers. Finally, the relatively rational load case gained by calculation was taken as the background, to further study the stiffness of cross tie beam on the seismic reaction of the bridge. The results of the study indicate that the variation of the location of cross tie beams has palpable influence on the transverse displacement of the main beam, load bearing condition of the bearings, pier-top transverse displacement and the pier base torsional moment of the curved beam bridge un- der seismic reaction. The condition that the cross tie beams are uniformly distributed along the pier columns is the most favorable condition for the seismic reaction of the bridge. The rational increase of the stiffness of cross tie beams can reduce the seismic reaction of the bridge.