山区高低墩梁式桥地震响应特性研究

Study on Seismic Response Characteristics of High and Low Pier Girder Bridge in Mountainous Area

由于山沟河谷等地形复杂,在山区桥梁建设中,高低墩桥梁较为常见。高低墩桥梁相邻桥墩高差相差较大,结构刚度也存在差异,在地震作用下,高低墩桥梁的地震响应和破坏形式也有所区别,因此有必要针对高低墩梁式桥地震响应特性进行分析。结合临淄至临沂段工程实例,以高低墩梁式桥为对象进行地震响应特性研究,主要得到以下结论:(1)通过计算桥墩的墩顶抗侧刚度和墩底内力分布,分析了横向存在高差及不同横系梁数量工况下桥梁的地震响应,得出了高低墩墩顶抗侧刚度与墩底内力分布规律及受力特点;(2)在顺桥向地震作用下,桥梁低墩受力较大;(3)在横桥向地震作用下,桥梁高墩承担了受力作用。

High and low pier bridges are common in mountain bridge construction because of the complex terrain such as valleys and valleys.The height difference between adjacent piers of high and low pier bridges is large,the structural stiffness is also different,and the seismic response and failure mode of high and low pier bridges are also different under the earthquake action.Therefore,it is necessary to analyze the seismic response characteristics of high and low pier beam bridges.Combined with the Linzi to Linyi section project,the seismic response characteristics of high and low pier girder bridges are studied,and the following conclusions are drawn:(1)By calculating the pusher stiffness of the pier top and the internal force distribution of the pier bottom,the seismic response of the bridge under the condition of transverse height difference and different number of transverse beams is analyzed,and the distribution law and stress characteristics of pusher stiffness of the pier top and internal force distribution of the pier bottom are obtained;(2)The stress on the low pier of the bridge is larger under the earthquake action along the bridge;(3)Under the transverse seismic action,the high pier of the bridge bears the force action.