PFC/FLAC 3-D coupled flexibility for natural gas hydrate numerical simulation triaxial experimental study

In this study, based on the PFC-FLAC discrete-continuous coupled analysis method, we constructed a model of gas hydrate-bearing sediments (GHBS) and conducted triaxial compression numerical simulation experiments. The results show that high confining pressure (>5 MPa) destroys the cementation of hydrate, and the stiffness of GHBS specimens increases with increasing confining pressure. The strength and stiffness of highly saturated (>40%) GHBS specimens increase with the increase of saturation, but the destructive brittleness increases as well. In terms of microscopic contact force, the enclosing pressure effect inhibits the particle motion and the GHBS specimens show anisotropy after loading damage. The results of this study contribute to a better understanding and prediction of the macroscopic and microscopic mechanical properties of gas hydrate sediments, which is of great significance for the safe and efficient exploitation of gas hydrates.