DEM simulation of triaxial compression tests on MHBS under different back pressures

Abstract

This paper investigates the mechanical behavior of Methane Hydrate-Bearing Sediments (MHBS) at different back pressures via the distinct element method (DEM). A series of triaxial compression test were carried out in order to analyze the micro- and macro-mechanical behavior under different back pressures, e.g. stress–strain relationship, void ratio and mechanical coordination number. Numerical results show that: the stress-strain relationships of MHBS exhibit more obvious strain softening characteristics at a lower confining pressure and higher back pressure. The final void ratio increases as back pressure increases. The increasing rate of the total mechanical coordination number with back pressure was significantly lower than that of hydrate cementation mechanical coordination number.