Analysis of the Model Used to Predict Continuous Deformations of the Land Surface in Areas Subject to Discontinuous Deformations—A Case Study

Abstract

This article analyses and evaluates the model used by the Jastrzebie Coal Company in Poland to forecast the values of continuous deformations of land surfaces caused by underground mining. Particular attention is paid to the values of terrain inclinations, which cause significant deflections of buildings located in mining areas affected by exploitation. The inclination forecasts were made using Bialek’s model, with the values of its parameters determined in situ and after completion of the exploitation of a longwall. The obtained results were compared with the values of the terrain inclinations calculated from the results of geodetic measurements carried out at observation points located near the buildings and discontinuous linear deformations (i.e., the ground steps). The conducted research shows that the correlations between the absolute values of the practical inclinations and the values of the theoretical inclinations were rather weak, as the values of their correlation coefficients did not exceed 0.24. The tested model underestimated 45.5% of the values of the inclinations observed in situ by an average of −53.5%. The model values of the inclinations for the remaining observed inclinations (54.5%) were overestimated by an average of 461.9%. The largest anomalies were obtained in the case of inclination values from points located near the ground steps. The effectiveness of predicting inclination values with a commonly used model is strongly reduced when discontinuous linear deformations appear. Nonetheless, it reflects well the mining area categories.