Numerical study of the effects of in-situ stress on high-energy gas fractures propagation in laminated rock masses based on peridynamics

Abstract

The aim of this study is to investigate the propagation pattern of high-energy gas fractures in laminated rock masses by considering different in-situ stress characteristics. To this end, a numerical model was constructed in the framework of the peridynamic theory that considers the combined effect of dynamic and quasi-static loading of high-energy gas to fracture the laminated rock mass, and the validity of the model was evaluated by comparison with laboratory experiments. Accordingly, the effects of the in-situ stress magnitude, vertical in-situ stress distribution, and horizontal in-situ stress difference between strata on the propagation of fractures in laminated rock masses were investigated. The results showed that an increase in the in-situ stress is not conducive to the propagation of fractures in the laminated rock mass. Under anisotropic in-situ stress conditions, fractures were more likely to cross the interface as the stress difference between the vertical and horizontal directions increased. As the horizontal in-situ stress difference between the unfractured and initially fractured layer increased, it became increasingly difficult for the fracture to cross the interface and the fracture extension length decreases. The results can serve as reference for the analysis of the propagation behavior of high-energy gas fractures in subsurface laminated rock masses.