铁道建筑

为确保换轨车进场时在已经松开数组扣件的钢轨上运行的安全性，本文建立车-轨-基础耦合模型，研究了松开扣件组数和外轨超高对换轨车运行安全性的影响，并给出扣件策略建议。结果表明：换轨车的安全性受松开扣件组数与超高共同影响。超高越大，车辆脱轨系数越大；松开扣件组数增加会减弱轨道的约束作用。车辆轮重减载率呈现轮对中间大、两端小的空间分布，“松20留1”时取得最大值，为0.577 1；松开扣件组数较少时，超高越大，轨距扩大量越大；随着松开扣件组数的增加，轮轴横向力、车体垂向加速度呈减小趋势，轨距扩大量和钢轨应力先增大后平稳变化。为充分保障换轨车作业期间安全运行，建议超高为0、40、60、95、120 mm时，分别采用“松15留1”“松12留1”“松10留1”“松8留1”“松6留1”的扣件策略。

To ensure the operational safety of the rail replacement vehicle running on rails with several groups of loosened fasteners when entering the site， this paper establishes a vehicle-rail-foundation coupling model， studies the influences of the number of loosened fastener groups and outer rail superelevation on the running safety of the rail replacement vehicle， and puts forward fastener strategy suggestions. The results show that the safety of the rail replacement vehicle is jointly affected by the number of loosened fastener groups and superelevation. A larger superelevation leads to a higher vehicle derailment coefficient; the increase in the number of loosened fastener groups weakens the restraining effect of the track. The wheel load reduction rate presents a spatial distribution feature of larger values in the middle wheelsets and smaller values at the two end wheelsets， reaching the maximum value of 0.577 1 under the "loosen 20 retain 1" scheme. When the number of loosened fastener groups is small， a larger superelevation results in a larger gauge widening amount. As the number of loosened fastener groups increases， the wheelset lateral force and car body vertical acceleration show a decreasing trend， while the gauge widening amount and rail stress first increase and then change stably. To fully guarantee the safe operation of the rail replacement vehicle during the operation period， it is recommended to adopt the fastener strategies of "loosen 15 retain 1"， "loosen 12 retain 1"， "loosen 10 retain 1"， "loosen 8 retain 1" and "loosen 6 retain 1" when the superelevation is 0， 40， 60， 95 and 120 mm respectively.