Research purposes: In permafrost regions,secondary harmful frozen soil phenomena can be formed by constructing subgrade engineering,and the secondary harmful frozen soil has many harmful impacts on buildings such as railway, highway roadbed. Studying the formation mechanism and development of the adverse phenomenon about frozen soil in permafrost regions has very important significance for controlling the happening and development of the secondary harmful frozen soil,and at the same time for guaranteeing the stability and safety of the engineering. In this article,we put forward the prevention of secondary disasters and engineering protection measures by analysising the thaw- frozenlandslide in secondary harmful frozen soil phenomena.
Research conclusions: In this paper,we studied the formation mechanism and changing process of secondary harmful frozen soil in permafrost regions and got the following conclusions:(1)Thermal differences exist between shady slope and sunny slope of roadbed,melting depth in sunny slope is bigger than shady slope when absorbing heat,and the effect of shady and sunny slope on the depth of roadbed melting cannot be ignored;(2)Considering the seepage effect,roadbed transverse inhomogeneous deformation will increase,which will form the disease of roadbed longitudinal cracks and have serious influence on the stability of the roadbed;(3)In this paper, we provide some theoretical foundations about the engineering construction m permafrost regions,which have reference meaning for controlling the secondary harmful frozen soil.