Approximation parameters of mining terrain subsidence induced by a multi-seam exploitation of hard coal deposits

Underground mining exploitation of hard coal deposits causes vertical displacements of terrain surface and a rise of subsidence trough on it. It's very important to make predictions of mining exploitation influences with a high accuracy. Evaluation of computational models applied in forecasting of exploitation effects is made on the basis of comparing forecasted values of deformation indicators with their average measured values. In this case subsidence of terrain surface caused by an exploitation of the 338/2, 358/1 and 341 hard coal seams have been observed. They on an observational line No. 8 after the end of exploitation in the 338/2, 358/1 coal seams and the 338/2, 358/1, 341 coal seams have been measured. Average values of measured subsidence on the way of approximation have been obtained. Approximation by the use of polynomials has been done. There a polynomial order n and a sections number k of approximating function on the basis of minimalization of a value of variability coefficient of random dispersion of observed subsidence M_W have been chosen.