无砟轨道层间冻胀特性研究

Study on Frost-heaving Characteristics of Interlayer of Ballastless Track

针对严寒、富水地区高速铁路无砟轨道层间冻胀问题,采用有限元软件,利用升温方法对离缝区域材料施加温度荷载使其体积膨胀来模拟冻胀,开展了无砟轨道层间冻胀特性研究。结果表明:无砟轨道层间冻胀可使钢轨、道床板产生类似于半波正弦分布的上拱变形,但对行车平顺性影响较小;层间拉应力随离缝深度的增加在离缝深度小于1. 25 m时增加较快,在大于1. 25 m之后趋于稳定;层间拉应力随离缝长度的增加在离缝长度小于1. 00 m时基本呈线性增加趋势,在大于1. 00 m之后增加趋势变缓;层间拉应力随离缝开口量的增加而线性增加。建议加强富水地段排水措施,对长度大于1. 40 m、深度大于1. 25 m和开口量大于1. 60 mm的离缝及时进行注浆修复,以减小层间离缝的进一步扩展及层间伤损。

This paper focused on interlayer frost-heaving problem of ballastless track of high speed railway in cold and water-rich region.By using finite element software,the frost-heaving was simulated by rising material temperature in gap area to apply temperature load and then expand the volume,and the study on frost-heaving characteristics ofinterlayer of ballastless track was carried out.The results show that the frost-heaving ofinterlayer of ballastless track can make rail and track slab to produce uplift deformation similar to half-sine distribution,but which has little influence on the smoothness of train operation.The interlaminar tensile stress increases rapidly with the increase of gap depth when gap depth is less than 1.25 m,while tends to be stable when gap depth is more than 1.25 m.The interlaminar tensile stress increases linearly with the increase of the gap length when gap length is less than 1.00 m,while increases slowly when gap length is more than 1.00 m.The interlaminar tensile stress increases linearly with the increase of the gap opening.It is suggested to strengthen drainage measures in the water-rich region,and for the gap whose length,depth and opening are larger than 1.40 m,1.25 m and 1.60 mm respectively,grouting repair should be carried out timely in order to reduce the further expansion ofinterlayer gap and interlayer damage.