Numerical simulation of pore structure stress characteristics of coal and rock mass

In order to explore the stress distribution around the pores of coal and rock mass under different loading modes, the skeleton model of coal and rock mass with different pore shapes was constructed through CT three-dimensional reconstruction technology, and uniaxial and triaxial compression experiment simulations were conducted using ABAQUS software. The results showed that under uniaxial compression, the upper and lower regions of spherical pores showed tensile stress concentration, while the left and right regions showed compressive stress concentration. The stress concentration types in the long and short axis of elliptic pores were distinct with different dip angles. Under uniaxial compression, axial loading velocity affected the maximum values of Mises stress and σ₁ stress around spherical pores. In the process of triaxial compression, the pore structure still went through four stages of compaction, elasticity, plasticity and failure. The lower confining pressure made the "stress-strain" curve and "stress-time" curve highly coincide in the elastic stage. This study provides a new method for the study of coal and rock mechanics from the microscopic point of view.