Discrete Element Simulation of the Macro-Meso Mechanical Behaviors of Gas-Hydrate-Bearing Sediments under Dynamic Loading

Under the action of dynamic loadings such as earthquakes and volcanic activities, mechanical properties gas-hydrate-bearing sediments will deteriorate, leading to a decrease in stability hydrate reservoirs even inducing geological disasters submarine landslides. In order study effect loading on sediments, triaxial compression tests numerical specimens were carried out by using particle flow code (PFC2D), macro-meso behaviors investigated. The results show that frequency has small stiffness sediment, while it large peak strength. strength increases then decreases with increase frequency. same frequency, sediment amplitude, specimen amplitude. maximum shear expansion changes movement phase change point rearrangement particles. bearing capacity particles after rearrangement, more forward is, stronger plastic stage. dilatancy angle amount both linearly influence amplitude contact force chain, displacement, crack expansion, number cementation damage inside is mainly related average axial stress which subjected, cracks subjected. As rate increases, distribution zones becomes obvious.