Particle Flow Analysis of Mechanical Properties and Failure Behaviour in Composite Rock Strata with Holes

Abstract

Understanding the deformation failure behavior of the composite rock strata has important implications for deep underground engineering construction. Based on the uniaxial compression laboratory test of the specimens of composite rock strata containing holes, the microscopic parameters in the particle discrete element simulation are firstly calibrated. Then, the mechanical properties and failure characteristics of the composite rock strata with holes under different confining pressures are studied. The results show that different dip angles and confining pressures have significant effects on the peak strength and elastic modulus of the specimens. Under the same confining pressure, the peak strength and elastic modulus decrease first and then increase with the increasing dip angle. As the dip angle is constant, both the peak strength and elastic modulus gradually increase with the increase in confining pressure. It shows that the first area to be damaged in composite rock strata transfers from soft rock to hard rock with the increase in dip angle. With the increase in confining pressure, the range of tensile stress concentration area decreases substantially, while the range of compressive stress concentration area changes less.

Research of roadway deformation induced by mining disturbances and the use of subsection control technology

“…Bai and Wu analyzed the impact degree of multiple mining disturbances in tunnel through theoretical analysis and numerical simulations and showed that the superposition of multiple dynamic pressures on the working face made the support of the lower coal roadway invalid 19‐22 . Cheng studied roof movement and evolution of mining stress of excavation roadway in the process of close‐distance coal seam mining and analyzed the macro‐migration impact of close‐distance coal seam superposition mining on the overlying strata 23‐26 . Liu and Xu performed numerical simulation analysis of roof deformation and failure caused by mining in overlapping working faces and obtained the stress distribution characteristics of the overlying strata as well as the characteristics of deformation and failure in the condition of multi‐seam overlapping mining 27‐30 …”

“…[19][20][21][22] Cheng studied roof movement and evolution of mining stress of excavation roadway in the process of close-distance coal seam mining and analyzed the macro-migration impact of close-distance coal seam superposition mining on the overlying strata. [23][24][25][26] Liu and Xu performed numerical simulation analysis of roof deformation and failure caused by mining in overlapping working faces and obtained the stress distribution characteristics of the overlying strata as well as the characteristics of deformation and failure in the condition of multi-seam overlapping mining. [27][28][29][30] In addition, scientists have deeply studied the deformation control of dynamic pressure roadway.…”