| Based on G301 in Inner Mongolia, by surveying the distribution of patchy permafrost and investigating all kinds of trouble of subgrade and pavement, the reasons of trouble were analyzed and some measures that aim to trouble were put forward. A two-dimensional non-steady calculation model that accompanies phase transitions was suggested. Some main factors, including the grade of subgrade, the height of subgrade and the padding of subgrade, affecting thermal stability of subgrade are studied by the finite element method. Connected with test road and test in room, a systematic designed method of subgrade and pavement was first posed in patchy permafrost zone. Moreover on principle of choosing road material, it is necessary to seek optimal combination of performances between mechanics and calorifics. By analyzing the temperature field measured on the test road, mostly artificial permafrost table in the center of road is steady. It is showed that permafrost itself is being degradation because the intrinsic curve of annual average temperature had obviously presented form of transition and negative gradient. The annual average temperature of permafrost is comparatively high and the existing situation of permafrost is flimsy, so it is very sensitive to outside disturbance. If permafrost degraded father by disturbed, it is adverse to the construction of highway. In order to assort the environment with the road, it is necessary to study the relationship between the environment of permafrost and the construction of highway, and adopt suitable measures to conservation of environment. |
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