ABSTRACT
The article describes the results of uniaxial compression tests of rectangular specimens made of geomaterial with a view to investigate coal–rock contact conditions on a lab scale. Based on the acoustic sounding data, tomography was carried out to find spatial distribution of longitudinal wave velocity V in a specimen per stages of loading. Using the empirical relation V(s), the mean normal stress s was calculated and taken as the input data in the solution of an inverse problem for determination of boundary conditions. The model calculations show that under vertical compression, near slip sections of coal–country rock contact, areas of horizontal tension arise, which are the most probable sources of failure and outbursts.
