Abstract:Repeated freeze-thaw cycles cause changes in soil cohesion and internal friction angle,increasing the erodibility of the soil.This study discussed the variations of soil bulk cohesion and internal friction angle in the freeze-thaw cycles and analyzed the freeze-thaw effects on soil anti erodibility. The black soil was selected as the study object.The changing trend of cohesion and internal friction angle of the soil were invest-igated through indoor freeze-thaw experiments with consideration of different freezing cycles and various soil moisture contents. The results show that freeze-thaw cycles affected greatly the soil cohesion and slightly the internal friction angle. With increasing numbers of freeze-thaw cycles, soil cohesion decreased and then achieved a stable state after three freeze-thaw cycles.With the increase of soil moisture,soil cohesion reduced and then increased in individual freeze-thaw cycles. At same freeze-thaw temperature, soil cohesion was affected greatly in the first freeze-thaw cycle, and very little in the following cycles. In contrast to soil cohesion, internal friction angle did not change significantly in the whole process of freeze-thaw cycles.