Abstract:In the last researches,it is usually considered that rock revetment and cracked rock embankments have the thermal diode effects,which can protect the frozen soil beneath the embankments from thawing in high temperature regions. But this is not the case completely,the effect of the larger diurnal-nocturnal air temperature difference,and the strong wind in Qinghai—Tibet Plateau will weaken or vanish the thermal diode effects,which are mainly caused by the forced convection in slope. To study the heat transfer mechanism and the cooling effects on the permafrost of the ripraped embankment under different boundary conditions,four kinds of embankments are studied with numerical simulation as follows:(1) normal embankment,consisting of sandy soil without crushed rock layer;(2) open rock revetment;(3) insulation slope being covered with insulation material;and (4) enclosed embankment. It is concluded that the traditional rock revetment can not take the advantages of the thermal diode effects to the full extension,and it is not satisfactory in maintaining the permafrost. This kind of temperature field effect caused by forced convection through numerical method is proposed;and a new type rock revetment is put forward,which can also be called sunshade-blocking-wind rock revetment. Through the numerical simulation,it is found that the new kind of crushed embankment has a better cooling effect;at the same time,the sand blocking problem and the temperature difference of the south and north slopes caused by solar radiation are properly solved.