Experimental investigation on mining-induced strain and failure characteristics of rock masses of mine floor

Abstract

Underground mining is known to cause the deformation and failure of the surrounding rocks and frequently associated with water-inrush through the mine floor. In this study, in-situ strain tests along with borehole imaging measurements were utilized to investigate the deformation and failure characteristics of the rock mass of the mine floor caused by mining. We directly measured the strain and borehole images of the rocks in the mine floor at different depths in five coal mines in the Yanzhou mining area, China. We observed from plotting the increments of strain that mining caused and then led to the deformation and failure of the rock mass of the mine floor. The zone in the floor that was affected by stress from mining was over 170 m in length and decreases with depth. We also found that the depth of failure in floor of the five different coal mines varied between 8.4 to 20 m.