Seasonal freezing soil is a kind of special soil-water system in which there is ice crystal, and it is geology object composed of soil grain, ice, pore water, and gas.

季节冻土是一种含冰晶的特殊土水体系，由土颗粒、冰、孔隙水、气组成的四相地质体。

youdao

Since all the pore space is filled, pressure builds until the ice turns to liquid.

BBC: Doubts over water on Mars