大跨度小半径曲线连续梁桥地震响应分析

Analysis of Seismic Response of Long Span Continuous Girder Bridge with Small Radius Curve

为研究大跨度小半径曲线连续梁桥的地震响应,以现代有轨电车线路上一座(33.5+60.0+36.5)m三跨预应力混凝土曲线连续梁桥为例进行分析。采用MIDAS/Civil建立全桥有限元模型,计算不同约束条件下桥梁动力特性,并采用反应谱法对桥梁在地震作用下的位移和内力进行分析。分析结果表明:采用刚构-连续组合的曲线梁桥可以获得较好的内力响应及位移响应,有利于桥梁的抗震;对于大跨度、小曲线梁桥,位移响应最大时和内力响应最大时分别对应不同的激励角度,在考虑水平地震作用时应按不同的激励角度进行分析。对刚构-连续组合曲线梁桥采用固结刚度较大的桥墩,可以提高整个桥梁的刚度,减少整体的位移,有利于桥梁抗震。

In order to study the seismic response of long span continuous girder bridge with small radius curve,the(33.5+60.0+36.5)m three-span prestressed concrete curved continuous girder bridge in modern tram line was taken as an example.The full-bridge f inite element model was established by using MIDAS/Civil.The dynamic characteristics of bridge under different constraint conditions were calculated,and the displacement and internal force of bridge caused by seismic were analyzed by means of response spectrum method.The analytical results show that better response of displacement and internal force can be achieved by adapting curved rigid frame-continuous combined girder bridge,which is advantageous to the anti-seismic of bridge.For bridge with long span and small radius,the maximum displacement response and maximum internal force response correspond to different excitation angles respectively,therefore,the horizontal effect of seismic should be analyzed from different excitation angles.For curved rigid frame-continuous combined girder bridge,the piers with large consolidation stiffness can enhance the overall stiffness of bridge and reduce the overall displacement,which is advantageous to the anti-seismic of bridge.