Electroacoustic technique to study changes in the liquid phase state of frozen soils

We discuss experimental data, measuring techniques and interpretation of the electromechanical energy conversions in frozen soils. These conversions clearly depend on the unfrozen liquid state, its content, bulk distribution, initial concentration and ionic composition of the saturating pore solution. For saline frozen sand saturated with solutions of various compositions in the concentration range from 10(-4) to 1 mole l(-1) the collected data on the peculiarities of electroacoustic conversions reflect the presence of the unfrozen liquid phase and changes of its content and state in the wide temperature range from the beginning of freezing to the corresponding eutectic point, and even below it. The established features are the basis of a new physical method to study and control liquid phase changes in frozen soils during freezing and thawing processes.