Effects of pore spacing and pore diameter on mechanical properties of sandstone with uniformly distributed pores

To study the influence of pore spacing and pore diameter on the deformation and failure of rocks with uniformly distributed pores, a set of microscopic parameters was determined by using the indoor uniaxial compression test data of complete sandstone specimens and sandstone specimens with prefabricated single cracks and discrete element particle flow software simulation, and the uniaxial compression simulation test of sandstone specimens with uniformly distributed pores was carried out based on the microscopic parameters. The research results indicate that when the pore diameter is kept constant, the peak stress, crack initiation stress and elastic modulus of the specimen all show a decreasing trend with the decrease of pore spacing, and the failure form of the specimen changes from shear failure to splitting failure; when the pore spacing is kept constant, the peak stress, crack initiation stress and elastic modulus of the specimen show a decreasing trend with the increase of pore diameter, and the failure form of the specimen changes from splitting shear composite failure to shear failure; the failure of the specimen starts from the stress concentration around the pore, and finally, the cracks extend and penetrate due to the fracture of particle bonding. Notably, the tensile cracks of the specimen are significantly more than the shear cracks.