Comparison analysis of the theoretical and forecasted values of mining terrain curvatures with reference to their values caused by multi-deposit exploitation conducted at the great depth

In this article were presented the results of comparison analysis of mining terrain curvatures values, which were caused by a multiple exploitation of hard coal in several coal beds numbered 338/2, 341 and 358/1. The curvatures values (observed on the measuring line) were compared with their theoretical values calculated on the base of subsidence forecasted by the use of the Białek’s formula (with the values of its parameters determined from the survey results) and with the curvatures values modeled with this formula directly. On the base of this comparison, there was made an evaluation of effectiveness of made forecasts and conducted theoretical calculations. Taking into account the values of correlation coefficients and standard deviations between the ‘measured’ and theoretical, and forecasted graphs of curvatures, it was defined which graphs fit better to the real results of geodesic measurements. It should be marked that an exploitation of three coal beds was conducted by the longwall system with the roof rocks falling into the post-exploitation emptiness, at a great depth amounts from 600 m (the 338/2 coal bed) to 1,000 m (the 358/1 coal bed). The influences coming from the exploitation of these coal beds were observed within 10 years on 53 points of measuring line, which was located above the middle of the B – 2 longwall in the 338/2 coal bed and parallel to the runs of excavations in this coal bed. The surveys of the points heights and distances between the measuring points were done in the three- and four-monthly cycles. Based on these measurements, the values of mining terrain curvatures were designated