Depth of the mining exploitation and its progress in the time, and a random dispersion of observed terrain subsidence and their derivatives

Paper presents the own research results conducted on shaping of random dispersion of the observed deformation indicators of mining terrain, especially subsidence and their derivatives such as inclinations and curvatures. Research were carried out on two examples of the underground mining exploitation, which was done at the small and medium depths. In both cases exploitation took place in an intact rock mass and in the one seam. Hard coal was extracted by the use of the longwall system with a roof rocks cave-in. Exploitation influences were observed after termination of the next exploitation stages and on the two measuring lines, which were stabilized perpendicularly to the longwalls runs. There were calculated the values of the variability coefficients of a random dispersion of the measured deformation indicators depending on an exploitation development in the time and a depth of the performed works. Generally, it can be said that a random dispersion of deformation process of terrain surface grows together with an exploitation depth and an increase its scope, what is especially visible in case of curvatures.