列车制动对刚构桥上无缝线路梁轨相对位移的影响研究

基于有限元方法建立桥上无缝线路单层弹簧阻力模型,研究了刚构桥及相邻简支梁桥桥墩纵向水平刚度匹配关系对梁轨相对位移的影响。采用铁路上常用的3种跨度刚构桥进行对比计算分析,结果表明,在刚构桥全桥制动时,刚构桥桥墩纵向水平刚度在一个范围内,梁轨相对位移随着刚构桥相邻两侧简支梁桥桥墩纵向水平刚度的增加先降低后增加;小于该范围时,梁轨相对位移随着简支梁桥桥墩刚度的减小而减小;而大于该范围时,梁轨相对位移变化规律与小于该范围的规律相反;并且该刚度范围随着刚构桥总长度的增加而增大。对于60 m+100 m+60 m的刚构桥,上述范围为1 100¹ 400 kN//(cm·双线);当刚构桥桥墩刚度取定为1 100 kN/(cm·双线),简支梁刚度从800 kN/(cm·双线)降低到400 kN/(cm·双线)时,附加伸缩力降低,梁轨相对位移先降低后增加,采用归一化方法处理数据,得出最优刚度取值为455 kN/(cm·双线)。

Influence of Train Braking on Relative Displacement between Girder and Rail of Continuous Welded Rail upon Rigid-frame Bridge

The single spring resistance model of continuous welded rail upon bridge was established based on finite element method. And then the influence on the relative displacement between girder and rail was studied,which was caused by the longitudinal horizontal stiffness matching relationship between the rigid-frame bridge pier and the adjacent simply-supported bridge pier. Also,the rigid-frame bridges with three kinds of spans commonly used in railway were adopted so as to comparatively analyze with each other. The results show that: when the whole rigid-frame bridge is in braking,and if the longitudinal horizontal stiffness of the rigid-frame bridge piers is within a certain range,the relative displacement between girder and rail will decrease at first and then increases with the increasing of the longitudinal horizontal stiffness of the simply-supported bridge piers which are sited at either side of the rigid-frame bridge; if being less than this range,the relative displacement between girder and rail will decrease with the decreasing of the pier stiffness of the simply-supported bridge; and if being larger than this range,the change rule of the relative displacement between girder and rail will be contrary to that of being less than this range. The above-mentioned stiffness range will increase as the overall length of the rigid-frame bridge extends. For the( 60 + 100 + 60)-m rigid-frame bridge,this range is about 1 100 1 400 kN//(cm·双线);当刚构桥桥墩刚度取定为1 100 kN/(cm·双线),简支梁刚度从800 kN/(cm·双线)降低到400 kN/(cm·双线)时,附加伸缩力降低,梁轨相对位移先降低后增加,采用归一化方法处理数据,得出最优刚度取值为455 kN/(cm·双线)。The single spring resistance model of continuous welded rail upon bridge was established based on finite element method. And then the influence on the relative displacement between girder and rail was studied,which was caused by the longitudinal horizontal stiffness matching relationship between the rigid-frame bridge pier and the adjacent simply-supported bridge pier. Also,the rigid-frame bridges with three kinds of spans commonly used in railway were adopted so as to comparatively analyze with each other. The results show that: when the whole rigid-frame bridge is in braking,and if the longitudinal horizontal stiffness of the rigid-frame bridge piers is within a certain range,the relative displacement between girder and rail will decrease at first and then increases with the increasing of the longitudinal horizontal stiffness of the simply-supported bridge piers which are sited at either side of the rigid-frame bridge; if being less than this range,the relative displacement between girder and rail will decrease with the decreasing of the pier stiffness of the simply-supported bridge; and if being larger than this range,the change rule of the relative displacement between girder and rail will be contrary to that of being less than this range. The above-mentioned stiffness range will increase as the overall length of the rigid-frame bridge extends. For the( 60 + 100 + 60)-m rigid-frame bridge,this range is about 1 100 1 400 kN /( cm·( double tracks)). When the stiffness of rigid-frame bridge pier is determined as 1 100 kN/( cm·( double tracks)),and at the same time the stiffness of simply-supported bridge pier is lessened from800 kN /( cm·( double tracks)) to 400 kN /( cm·( double tracks)),the additional expansion force will weaken,and the relative displacement between girder and rail will decrease at first and then increase.Finally,by using normalization method to process data,the optimal stiffness value of 455 kN /( cm ·( double tracks)) was obtained.