城市轨道交通大坡道及小半径曲线地段轨道结构受力和变形特性分析

采用有限元法建立了大坡道及小半径曲线地段的长枕埋入式轨道和浮置板轨道结构模型,分析列车紧急制动下坡通过曲线时的钢轨受力、轨道结构底部支反力及轨道板的位移。结果表明:浮置板轨道结构的钢轨纵向力大于长枕埋入式轨道钢轨纵向力;长枕埋入式轨道结构底部纵向支反力大于浮置板轨道隔振弹簧的纵向支反力,垂向支反力小于浮置板隔振弹簧垂向支反力。列车转向架处于浮置板两端时会引起轨道板垂向位移增大,对剪力铰影响较大;纵向位移自列车荷载作用处向浮置板两端递减,纵向位移最大值约为0.30 mm;列车通过曲线时易引起浮置板向外轨方向发生横向位移和倾斜。

Mechanical and Deformation Characteristics of Rail Transit Track with Long Steep Gradient and Small Radius Curve

Based on the finite element method,a modle of long sleeper buried ballastless track and floating slab track on the steep gradient and small radius curve line is established,to analyze the force on rail,the reaction force and the displacement of slab in case of emergency downhill breaking.The results shows that the longitudinal force on rail of floating slab track is larger than that of the sleeper buried ballastless track;the longitudinal reaction force of the sleeper buried ballastless track on the bottom is larger than that of the floating slab track,while the vertical reaction force is smaller than that of the floating slab track.The vertical displacement is sharply increased when the train bogie is on both sides of the slab,which would have an adverse effect on the shear hinge;the longitudinal displacement is decreased progressively from the vehicle load location to the slab end,the maximum longitudinal displacement is about 0.3 mm.The transverse inclination to the high rail direc tion might occur when a train passes through the curve.