道砟胶分段固化道床动力性能测试与分析

Dynamic testing and analysis of ballasted track of different stiffness sections using polyurethane ballast reinforcement technique

为解决有砟-无砟轨道过渡段病害较严重的问题,在部分线路上采用道砟胶分段固化道床技术控制道床的沉降。道床固化后,对过渡段固化道床进行动态测试。研究结果表明:道砟胶分段固化后的线路满足安全性指标;分段固化后的道床动态刚度逐段增大,道床局部黏结断面、部分黏结断面、全黏结断面分别达到91,126和273k N/mm,较有砟道床断面分别提高1.28倍、1.75倍和3.78倍;轮轨力、减载率、钢轨垂向加速度自有砟轨道至道床全固化断面逐渐增大;钢轨垂向位移、轨枕垂向位移、轨枕垂向加速度自有砟轨道至道床全固化断面逐渐减小,实现了从无砟轨道到有砟轨道的过渡效果。

The serious degradation of the railway track is observed in the transition zones between the ballasted track and the ballastless track.The degradation is aroused by the abrupt variation of the track stiffness which is led by the vertical settlement of the track.In order to solve these problems,the polyurethane ballast reinforcement technique was adopted to form a continuous and even stiffness transition in the ballasted bed which was divided into three different stiffness sections.The dynamic test was carried out for the track using the ballast reinforcement technique.The results show that the safety index of the track line can be achieved using the ballast reinforcement technique.The dynamic stiffness of the ballasted bed in the three section is 91,126 and 273 kN/mm,respectively,which is corresponding to different amounts of bonding areas from small to large.And the stiffness of the ballasted bed with these three bonding areas increases by 1.28 times,1.75 times and 3.78 times,respectively,contrasted to that of the common ballasted bed.Thus,the wheel/rail vertical force,the wheel unloading ratio,the vertical displacement of the rail and the sleeper gradually increase,but the vertical displacement of the rail,the vertical displacement of the sleeper,and the vibration characteristics of the sleeper gradually decrease from the low stiffness section to the high stiffness section.In general,the ballasted track using the polyurethane ballast reinforcement technique achieves the best dynamic stiffness transition effect of the track line.