车辆的运行会使大跨度斜拉桥产生纵向运动,为研究列车荷载作用下大跨度铁路斜拉桥主梁的纵向运动量、纵向受力性能以及塔梁连接刚度的影响,以韩家沱长江大桥为工程背景,采用车一桥耦合振动分析方法,计算了主梁纵向位移和速度响应,为纵向阻尼器的设计参数优化提供了依据;分析了塔梁问纵向相互作用力,给出了支座摩阻系数的上限值;计算了系统总刚度与弹性连接刚度的关系,明确了弹性连接刚度与纵向总刚度及主梁纵向位移之间的关系。研究表明:CRH2动车组对桥梁结构纵向动力响应的影响更明显;增加支座摩阻力可抵消由列车运行引起的结构体系纵向作用力,从而抑制主梁纵向运动;系统纵向总刚度随塔梁间弹性连接刚度的增大而增大,但非线性关系明显。
The vehicles moving on the long span cable-stayed bridge will cause longitudinal movement of the bridge. To study the longitudinal movement amount and longitudinal force be- havior of the main girder of the long span railway cable-stayed bridge and the influence of connec- tion stiffness of the pylon and girder under the action of train load, the Hanjiatuo Changjiang Riv- er Bridge was cited as an example, the longitudinal displacement and velocity responses of the main girder were calculated, using the vehicle-bridge coupling vibration analysis method and the basis for optimizing the design parameters of the longitudinal dampers was provided. The longitu- dinal interaction forces between the pylon and girder were analyzed and the upper limit values of frictional coefficients of the bearings were given. The relationship between the system longitudi- nal total stiffness and elastic connection stiffness was calculated and the relationship among the e- lastic connection stiffness, longitudinal total stiffness and longitudinal displacement of the main girder was made clear. The results of the study demonstrate that the influence of the CRH2 Train Group on the longitudinal dynamic responses of the bridge structure is more significant. The in- crease of the fictional resistance of the bearings can offset the longitudinal action force of the structural system caused by the moving trains, hence, can suppress the longitudinal movement of the main girder. The system longitudinal total stiffness increases with the increase of the elastic connection stiffness of the pylon and girder, but the nonlinear relationship is significant.