Modeling the thaw boundary in broken rock zones in permafrost in the presence of surface water flows

摘要

The behavior of the thaw boundary of a permafrost rock zone is investigated in connection with the melting of frozen highly fractured rock zones that is caused by water movement across these zones. This behavior is different from that of frozen earth due to the large frozen pore volumes. A computational method to track the movement of the thaw boundary on the basis of the finite element analysis is presented and the method for determining some of the appropriate input parameters is discussed. The differences in thaw boundary movement is shown clearly by the analysis of heat flux in the two cases considered. The computational method is used to predict the melting depth of a frozen fractured rock mass in a permafrost region, and the comparison of the computed results with engineering cases in practice is used to verify the computational method.