高等减振轨道过渡段设置方案研究

Research on the Setting Plan of the Transition Section of the High-level Vibration Reduction

研究目的:整体道床无砟轨道与高等减振无砟轨道刚度差异较大,连接处钢轨垂向位移和受力变化剧烈,本文建立车辆-轨道-过渡段动力分析模型,对比8种过渡段设置方案对钢轨垂向位移、钢轨挠度变化率和车体垂向加速度的影响,研究高等减振过渡段结构最优设置方案,并分析不同车速下列车垂向加速度以及钢轨挠度变化率的变化规律。研究结论:(1)较不设置过渡段,设置过渡段后钢轨最大挠度变化率下降幅度在50%~61%,车体振动加速度下降幅度在43%-65%;(2)过渡段长度从2块板增至3块板时,同一过渡级中钢轨最大挠度、车体垂向加速度变化不甚明显;(3)建议二级过渡采用刚度为0.03N/mm^(3),三级过渡采用刚度为0.046N/mm^(3)-0.03 N/mm^(3);(4)当车体速度由80 km/h增至140 km/h时,车体最大垂向加速度由0.026 m/s^(2)增至0.046 m/s^(2),增幅为77%;(5)本研究成果可为城市轨道交通高等减振过渡段工程设计提供参考。

Research purposes:Due to the large difference in stiffness between monolithic concrete bed prefabricated slab tracks and high-level vibration reduction prefabricated slab tracks,there are drastic changes in the vertical displacement and force of the rail at the joint.This paper establishes the dynamic analysis model of the vehicle-track-transition section,compares the effects of eight transition section settings and no settings on the rail vertical displacement,rail deflection rate and train vertical acceleration,and studies the optimal setting plan for the transition section of the slab.This paper also analyzes the laws of train vertical acceleration and rail deflection rate under different vehicle speeds.Research conclusions:(1)After setting the transition section,compared with no transition section,the maximum deflection rate of the rail decreases by 50%〜61%,and the vehicle body vibration acceleration decreases by 43%〜65%.(2)When the length of the transition section is increased from 2 plates to 3 plates,the changes of the maximum deflection of the rail and the vertical acceleration of the train are not very obvious.(3)The rigidity of 0.03 N/mm^(3)should be adopted for the secondary transition,and the rigidity of 0.046 N/mm^(3)-0.03 N/mm^(3)should be adopted for the tertiary transition.(4)When the speed increases from 80 km/h to 140 km/h,the maximum vertical acceleration of the car body increases from 0.026 m/s^(2)to 0.046 m/s^(2),with an increase of 77%.(5)The research results can provide reference for the engineering design of high-level vibration reduction transition of urban rail transit.