Multi-pore approximation model for simulation of macroscopic mechanical properties and failure behavior of coal under uniaxial compression

Under the influence of coal formation, evolution, and mining disturbances, the pores and cracks are the main characteristics of coal. Understanding how these characteristics affect the macroscopic properties and failure evolution of coal is crucial for ensuring safe coal mining. This study presents a multi-pore approximation model to investigate the impact of pore parameters, such as porosity and pore distribution, on the macroscopic properties, stress distribution, and failure characteristics of porous coal. Results show that higher porosity weakens the coal strength and accelerates its failure, while pore distribution significantly influences stress distribution and failure patterns. Internal element failure mirrors pore distribution, with vertical variations in pore distribution being the primary factor influencing the total number of failure elements. Furthermore, porosity and pore distribution co-influence coal failure, with a quadratic relationship observed between porosity and the total number of failure elements.