NUMERICAL ANALYSIS OF RAILWAY EMBANKMENT PROTECTED WITH ROCK FILLS IN PERMAFROST REGION OF QINGHAI AND TIBET

To study the influence of the crushed rock slope protection on the temperature field of the embankment in permafrost region,finite element analysis is conducted,in which phase changes are taken into consideration to simulate the embankment with crushed rock slope protection layer of different thickness and the observation data of the climate and geological conditions in Qinghai-Tibet railway testing section are used as the upper boundary condition.The calculation results show that the crushed rock slope protection can enhance the stability of the embankment in permafrost region.The influence the crushed rock creates to the temperature field is relatively great near the toe of the embankment,and the crushed rock slope protection can prevent the embankment from longitudinal cracks to some extent.In practice,the thickness of the crushed rock layer can not be too thick.