中等减振梯形轨枕轨道结构关键设计参数

Key Design Parameters of Medium DampingTrapezoidal Sleeper Track Structure

为研究中等减振梯形轨枕轨道的动力学特性,采用直接刚度法建立了车辆-梯形轨枕轨道-隧道垂向耦合动力学模型,分析了减振垫垂向静刚度和梯形轨枕厚度对钢轨、轨枕和隧道动力响应的影响。结果表明:当减振垫静刚度在15~30 kN/mm时,减振效果均达到了中等减振要求,梯形轨枕减振垫的垂向静刚度可以根据环境敏感点的具体振动超标量进行选取;与普通整体道床相比,当梯形轨枕的板中减振垫垂向静刚度为25 kN/mm时,梯形轨枕在40 Hz以上的频率范围具有较好的减振效果;增加梯形轨枕厚度可以降低钢轨和轨枕的垂向位移,并通过增加参振质量的方式提高减振性能;当梯形轨枕厚度从0.15 m增至0.35 m时,钢轨垂向位移、轨枕垂向位移和隧道垂向加速度减小幅度达7.73%、和6.82%和18.18%;中等减振梯形轨枕轨道与普通整体道床衔接时,需要在梯形轨枕铺设段设置3块5.8 m过渡梯形轨枕,过渡梯形轨枕的减振垫静刚度应优先按照三级刚度过渡方案进行选取。

To study the dynamic characteristics of medium damping trapezoidal sleeper tracks,a vehicle trapezoidal sleeper track-tunnel vertical coupling dynamic model was established using the direct stiffness method.The influence of the vertical static stiffness of the damping pad and the thickness of the trapezoidal sleeper on the dynamic response of the steel rail,sleeper,and tunnel was analyzed.The results show that when the static stiffness of the damping pad is between 15~30 kN/mm,the damping effect meets the moderate damping requirements.The vertical static stiffness of the trapezoidal rail sleeper damping pad can be selected based on the specific vibration superscales of environmental sensitive points.Compared with ordinary integral track beds,when the vertical static stiffness of the damping pad in the trapezoidal sleeper plate is 25 kN/mm,the trapezoidal sleeper has better damping effect in the frequency range above 40 Hz.The increase of trapezoidal sleepers thickness can reduce the vertical displacement of steel rails and sleepers,and improve the damping performance by increasing the vibration mass.When the thickness of the trapezoidal sleeper increases from 0.15 m to 0.35 m,the vertical displacement of the steel rail,the vertical displacement of the sleeper,and the vertical acceleration of the tunnel decrease by 7.73%,6.82%,and 18.18%,respectively.When connecting the medium damping trapezoidal sleeper track with the ordinary integral track bed,it is necessary to set up three 5.8 m transition trapezoidal sleepers in the laying section of the trapezoidal sleeper.The static stiffness of the damping pad of the transition trapezoidal sleeper should be prioritized according to the three-level stiffness transition scheme.