重载运输条件下桥墩横向振幅的影响因素分析

An Analysis of the Influential Factors of the Transverse Amplitude of the Pier in the Conditions of the Heavy-Load Transportation

随着我国重载运输的持续发展,列车编组增加,车辆轴重增大,运营密度增大,现役重载桥梁出现横向振动过大危及行车安全的现象,研究表明桥墩墩顶横向振幅直接影响桥跨结构的横向振幅,因此研究桥墩的横向振动的影响因素对控制桥跨横向振动十分必要。以朔黄铁路中比重较大的矩形板式墩为研究对象,采用理论分析、有限元模拟分析结合现场实测的方法,研究了列车行驶速度、桥墩高度及轴重对墩顶横向振幅的影响规律。结果表明,随着速度的增大,墩顶横向振幅呈先增大后减小趋势;桥墩横向自振频率越大,墩顶横向振幅最大值所对应的速度越大;随着墩身高度增加、列车轴重增大,墩顶横向振幅均呈增大趋势。

With the continuous development of the heavy-load transportation, the train formation is increasing, the vehicle axialload is increasing, and the operational density is also increasing, as a result of all of which the too great transverse vibration ofthe heavy-load bridge may endanger the safety of the traffic of the heavy-load bridges in service. Research shows that the horizontalamplitude of the pier top may directly affect the horizontal amplitude of the bridge span structure. so its extremely necessaryto study the influential factors of the transverse vibration of the bridge pier to control the lateral vibration of the bridgespans. With the rectangular plate-type pier which occupies the larger proportion of the Shuo-Huang Railway as the object of ourresearch, the influential laws of the running speed of the train,the height of the pier,and the axial loads on the transverse vibrationamplitude of the pier top are studied by means of theoretical analyses,and the finite element analysis method combined withthe site surveyed results. Results show that with the speed increasing,the horizontal amplitude of the pier top tends to increasefirst and then to decrease. The greater the horizontal natural frequency is,the greater the corresponding speed to the speed of the maximum lateral amplitude of the pier top will be larger. With the increase in theheight of the pier body, and the increase in the axial load of the train, the horizontal amplitude of the pile top tends to increase.