带纵坡曲线梁桥地震响应试验研究

为了研究带纵坡的曲线梁桥在地震作用下的动力响应特性,以某匝道桥为原型,设计制作几何相似比1∶10的缩尺模型进行振动台试验,分别沿X向、Y向和X+Y向输入地震动,分析水平地震作用下曲线梁桥的地震响应。结果表明:地震波X向输入使主梁产生平动兼有转动,在平面内产生弯曲,Y向输入时,主梁的转动效应较小;高墩对桥墩位移具有一定的放大作用,桥墩位移响应与地震波输入方向之间的角度越小,桥墩位移越显著,固定墩在地震波双向输入时更加不利;支座位移与地震波输入方向之间的角度越小,支座位移越大;地震波X向输入时,低墩处容易产生落梁、高墩处主梁容易与桥台挡块碰撞,Y向输入时,高墩处容易产生落梁、低墩处主梁容易与桥台挡块碰撞。

Experimental Study on Seismic Response of Curved Girder Bridge with Longitudinal Slope

To study the dynamic response of a curved girder bridge with the longitudinal slope under seismic action,taking a ramp bridge as an original bridge,we designed and produced a 1∶10 scale model of curved bridge.Furthermore,seismic simulation shaking table tests with the seismic waves input in X-direction,Y-direction and X+Y-direction were carried out.The influence of horizontal seismic action on seismic response of curved girder bridge was analyzed.The results show that the seismic waves input in X-direction can cause the translation and rotation of the main girder,and cause the in-plane bending of the main girder.The rotation effect of the main girder caused by Y-direction input is smaller.High piers can amplify the effect of pier displacement.The smaller the angle between the pier displacement and the direction of the seismic wave input is,the more obvious the displacement response of the pier will be.The fixed pier is more disadvantageous to displacement response in bidirectional seismic waves input.The smaller the angle between the bearing displacement and the direction of the seismic wave input is,the larger the bearing displacement will be.When seismic wave is input in X-direction,it is easy to cause the girder falling at the low pier and collisions at the high pier.When seismic wave is input in Y-direction,it is easy to cause the girder falling at the high pier and collisions at the low pier.