6GOERING D J, KUMAR P. Convective heat transfer in railway embankment ballast[A]. Thimus Ground Freezing 2000[C]. Rotterdam: Balkema Publishers,2000,31-36.
7SUN B, XU X, LAI Y, et al. Experimental researches of thermal diffusivity and conductivity in embankment ballast under periodically fluctuating temperature[J]. Cold Regions Scienceand Technology, 2004, 38 (2/3):319-227.