f Use of geophysical methods for investigating the saturation of rock-mass

The subsidence of overlying rocks in mining areas There are severe environmental disturbances in mining areas due to inhomogeneous subsidence of rocks, which are located over the exploited seams. The subsidence is a result of field stress, which occurs when the void under the earth surface destabilizes the mechanical equilibrium in the rock masses and starts going into a new equilibrium state. The stresses may act directly on grains or through hydraulic pressure. They may produce elastic or inelastic deformations, both of which are measurable by geophysical methods. The deformation due to hydraulic pressure is considered in this paper.