Fracture Characteristic and Instability Mechanism of Sandstone with Parallel Double Fissures Based on Discrete Element Method
Studying the influence of double fissure on the stability and fracture characteristics of rock masses can help understand the interaction mechanism between fissures.Using PFC2D to established a numerical model of paralleled double fissure sandstone samples with different spatial distribution structures and conducting uniaxial compression tests on them.Analyzed the loaded damage characteristics,microcrack evolution,and stress field distribution,and explored the instability mechanism of the samples combining macroscopic failure characteristics.The results show that the different spatial distributions of three types of double fissures in differences in the progressive damage process and mechanical properties of sandstone,and affect the distribution,quantity,and inclination of microcracks,significantly influencing the degree of rock bridge damage and forming different fracture zones.The peak stress distribution of different models was compared using equivalent stress cloud maps,and the influence of different spatial distribution structures of fissures on the load-bearing surface and compressive stress transmission path of the specimen was explored from the perspective of external forces,combined with macroscopic failure characteristics.The research results can provide reference value for engineering practice and rock mechanics research.