Engineering disasters occur frequently and violently with the increase in mining depth, which is mostly due to insufficient study on the failure mechanism of the deep rock mass. In this paper, theoretical and experimental researches on the failure behaviors and deformation control of deep surrounding rock in recent years were reviewed. Macro/meso failure mechanism of deep rock or coal–rock combined body under different loading conditions have been systematically investigated. Stress gradient failure theory of surrounding rock, uniform strength support in the deep roadway, and the analogous hyperbola movement model of overlying strata were preliminary established and a combined grouting control technology for surface and underground was proposed. Abovementioned achievements are expected to offer theoretical bases and technical supports for the exploitation of China’s deep mineral resources in the future.
11 March 2021 in Rock Mechanics and Rock Engineering
To accurately predict coal burst hazards and estimate the failure of coal pillars in underground coal mining systems, it is of great significance to understand the mechanical behavior of coal-rock bimaterial composite structures. This paper presents experimental and numerical investigations on the response of rock-coal, coal-rock, and rock-coal-rock bimaterial composite structures under triaxial compression. The triaxial compression experiments are conducted under confining pressures in the range of 0–20 MPa. The resulting inside fracture networks are detected using X-ray-based computed tomography (CT). The experimentally observed data indicate that the mechanical parameters of the rock-coal-rock composites are superior to those of the rock-coal and coal-rock combinations. After compression failure, the coal-rock combination specimens are analyzed via X-ray CT. The results display that the failure of the coal-rock composite bodies primarily takes place within the coal. Further, the bursting proneness is reduced by increasing confining pressure. Subsequently, the corresponding numerical simulations of the experiments are carried out by using the particle flow code. The numerical results reveal that coal is vulnerable with regard to energy storage and accumulation.
20 June 2018 in Rock Mechanics and Rock Engineering