Assessment of Rock Mass Stresses and Deformations Around Mine Workings Based on Three-dimensional Numerical Modelling

Authors: S . Prusek, S. Bock

This paper presents an example of application of three-dimensional modelling for the purposes of assessing condition of rock mass around a coal bunker located at a depth of 300 m. The calculations were performed using the Coulomb-Mohr criterion and the method of fi nite differences. The rock mass modelling was performed by means of the programme FLAC3D developed by HCItasca.

The software enables spatial modelling of considerable deformations and destruction of rock mass as well as resolving complex problems stepwise. The applied values of rock mass parameters were gained during underground investigations which included: macroscopic observation, penetrometer tests, introscopic tests and laboratory test on samples taken from the bunker’s lining and surrounding rocks. Based on that it was possible to assess the rock mass according to the RMR and GSI classifi cations, as well as to determine values of the key rock-mass parameters used in the numerical methods. Based on an analysis of the spatial stress-andstrain state of the rock mass around the coal bunker as well as taking into consideration the results of the underground tests and observations an assessment of the referred to working’s stability has been made.