ABSTRACT
Salt deposits development is always associated with the risk of waterproof stratum failure resulting in hazardous fresh water inflow in mine openings. Due to high solubility of salts this could lead to flooding and collapse of mine as a result of uncontrollable water inflow increase. Process of flooding is usually accompanied by increased subsidence rate and sinkhole formation on earth surface. Estimation of negative consequences of mine flooding is based as a rule on earth surface subsidence surveys and a priori expected evaluations of rocks dissolution. Depending on different assumptions and taking into consideration actual data from geophysical research complex (seismic prospecting, gravity measurements, electrical exploration etc.) the results obtained could differ greatly.
Geomechanical model that describes the process of salt covering rocks failure during accelerated deformations associated with rock dissolution of upper part of salt strata is presented in the paper. The conditions of subsidence transformation into dynamic phase with sinkhole formation on earth surface are considered for the case of First Berezniki Potash mine flooding.
