SIMULATION OF ENERGY SOIL LANDSLIDE INDUCED BY HYDRATE DISSOCIATION USING MATERIAL POINT METHOD

Abstract

Gas hydrate dissociation can pose adverse effects on the stability of the hydrate layer. Submarine landslides are likely to form if triggered by other factors. In this paper, finite element method and material point method are combined to study hazards of the potential energy soil landslide in Shenhu Sea Area of South China Sea. FEM is utilized to calculate the safety factor of the submarine slope under different gas hydrate dissociation quantities and the critical dissociation quantity which would induce a submarine landslide is 30%. Under the most dangerous condition(the hydrate dissociated totally), a hydro-mechanical coupled MPM is utilized to simulate the run-out process of the potential energy soil landslide based on the M-C strength criterion. The results show that the sliding distance can reach 1184 m under the most dangerous condition. The displacement mutation interface and the point reaching the maximum sliding distance obtained by two methods are consistent with each other. Under the most conservative condition, it is suggested not to construct any important marine engineering facilities within 1184 m downhill from the submarine energy soil slope. The analysis results can serve as a convenient reference for assessing the safety and environmental risk of gas hydrate exploitation in the future.