Free boundary problems arising in the freezing of soils in a bounded region. III. Hydrodynamics of the unfrozen phase. IV. Thermal stresses in the frozen phase

In this paper, the method of characteristics is utilized to construct unique solutions to Problems II and III stated in Part I, and we demonstrate the continuous dependence of these solutions on the respective initial and boundary data. Moreover, asymptotic estimates for the critical time of breakdown in these solutions are also obtained.