无砟轨道层间动水流速三维分布特性

Three-dimensional distribution character of water velocity in the interlayer of ballastless track

针对列车荷载下无砟轨道层间裂缝内的动水流速分布问题,应用流固耦合计算理论,建立层间裂缝内水流速度计算模型,采用多钢轨支点力的时序式加载模式,分析裂缝几何形态、列车运营状态等因素对水流速度的影响.结果表明：随着列车的趋近与远离,无砟轨道层间裂缝内的水流速度呈现周期性的正、负交替变化,其最大正、负水流速度均发生在裂缝出口处,在同一时刻,裂缝内可能会出现正、负水流速度区共存的现象;裂缝几何形态是影响水流速度分布的一类重要因素,水流速度大小与裂缝纵向长度呈先增加后趋于平稳的关系,与裂缝深度呈二次多项式的增加关系,与裂缝开口量呈一次反比减小的关系;列车运营状态是影响水流速度分布的另一类重要因素,水流速度大小与列车速度、列车轴重呈线性增加关系.

Aimed at the water velocity distribution inside the interbedded crack of ballastless track under the train load,the calculation model of water velocity was established on the basis of fluid-structure interaction calculation theory,and the influences of crack geometrical morphology and train operation condition on water velocity were analyzed by us ing the sequential loading mode of multiple rail support forces.Results show that as the train approaching and departing from the location of interbedded crack,the water velocity changes cyclically under the train load,and both the maximum positive and negative water velocity occur at the outlet of crack.Simultaneously,there may be a coexistence phenomenon of positive and negative velocity in the crack.The crack geometrical morphology is a class of important factors that effecting the distribution of water velocity,the value of water velocity is inversely proportional to the vertical crack aperture,and proportional to the quadratic polynomial of horizontal crack depth.But the value of water velocity increases firstly with the increase of longitudinal crack length,and then tends to be stable.The train operation condition is another class of important factors effecting the distribution of water velocity,the value of water velocity is linear with the axle load,and proportional to the train speed.