Evaluation of in situ stresses based on the surface displacement

Evaluation of in situ stresses is one of the most important aspects of any underground project. This paper analyses the existing methods of evaluation of in situ stresses along with a method of evaluating the ratio of horizontal and vertical stresses in situ by surveying the movements of surface rock. This method of evaluating in situ stresses emerged during the analysis of the surface movement due to the excavation of a barrier pillar between two panels filled with cemented backfill at an operating mine in Central Kazakhstan. The findings offered a simple and efficient method for estimation of in situ stresses based on the surface subsidence analysis. The method has been practically validated at three mines with various angles of the dip of orebody. Also, it helped to estimate rock pressure in coal mines with various steepness of seams, from flat to 70 degrees. The findings offered a simple and efficient method for estimation of in situ stresses based on the surface subsidence analysis.