In situ stress field inversion and its application in mining-induced rock mass movement

Based on a series of experiments in numerical simulation, the model boundary conditions for in situ stress field inversion and excavation are discussed. Study results indicate that roller boundary conditions are reasonable for the in situ stress field inversion before excavation simulation, while, as a closed system, changing the roller boundary conditions to fixed boundary conditions in the subsequent excavation is optimal when the dimensions of the model borders are greater enough than the zone of influence of the excavation. As a case study, a comparative study of the mining-induced ground movement in a steeply dipping mine is carried out in two different stress fields. The results show that the mining-induced ground movement in the high-level tectonic stress field clearly differs from that in the ideal self-weight stress field. Because of the steep occurrence and large thickness of the ore body, the mining-induced ground subsidence exhibits different characteristics at different mining stages in the practical tectonic environment. Further studies elucidate the causes of these differences and clarify the effects of high-level tectonic stresses on rock mass movement and deformation. Finally, based on GPS monitoring results on the ground surface, the current ground subsidence is evaluated and its development trend is predicted. (C) 2012 Elsevier Ltd. All rights reserved.