路基不均匀沉降对有砟轨道沉降影响的模型试验

Model Test Study of Influence of Differential Subgrade Settlement on Ballasted Track Settlement

摘要:

为研究路基不均匀沉降对有砟轨道沉降变形的影响,设计了1∶1有砟轨道模型试验系统.通过人为设定的空隙模拟路基不均匀沉降,采用激振器模拟列车振动荷载作用,研究了在有砟轨道变形稳定后,轨枕空吊前后路基不均匀沉降对有砟轨道沉降变形的影响.试验结果表明,余弦型路基不均匀沉降引起的轨道沉降变形曲线可用余弦型函数描述; 当路基的纵向不均匀沉降槽面积较小且未引起轨枕空吊时,轨面与路基纵向不均匀沉降槽的面积比为1,并据此明确了轨枕不发生空吊情况下路基不均匀沉降与有砟轨道轨面沉降变形之间的计算关系及其主要影响因素; 随着路基不均匀沉降继续增加,当轨面与路基纵向不均匀沉降槽的面积比小于1时,有砟轨道将出现轨枕空吊现象,并且面积比将随路基不均匀沉降的增加而减小.

Abstract:

To study the influence of differential subgrade settlement on the ballasted track settlement,a 1∶1 model test was designed.The differential subgrade settlement was simulated by designed void,and the dynamic train load was simulated by Centrifugal Exciter,then a study was made of the influence of differential subgrade settlement on the settlement of ballasted track before and after the sleeper is unsupported on the condition that the the settlement of ballasted track was stabilized.Experiment result shows that the curve of track settlement caused by differential subgrade settlement can be described by cosine function.When the area of differential subgrade settlement curve is small and doesn’t cause the sleeper to be unsupported,the ratio of the area of track settlement curve to differential subgrade settlement is 1.Based on those results,the calculation formula which is about ballasted track settlement caused by differential subgrade settlement is put forward,then the main causing factors are discussed.With the developing of differential subgrade settlement,once the ratio of the area of track settlement curve to the area of differential subgrade settlement is less than 1,the phenomenon that the sleeper is unsupported will appear and the ratio of area will decrease as the increase of differential subgrade settlement.