| This study concerns some conceptual aspects of a dynamically coupled solid-water-gas soil model. Contrary the mainstream in the geomechanics, both the compressibility of the water-gas mixture in the pores and the solid grain skeleton has been taken into account. While the compressibility of the water gas mixture depends on the pore pressure changes, that among other aspects drives the diffusion process of gas mass between free gas bubbles and the dissolved gas to a new equilibrium, the compressibility of the solid mass, especially for cohesive soils, is strongly determined by the stiffness of the hydrogen bonds. Therefore the applied stress has to be distinguished into an isotropic component related to the non-linear bulk modulus of the grain skeleton and the water-gas mixture and the shear behaviour due to the grain-grain interaction, which is strongly dependent on the effective stresses. Because of the several non-linear aspects of the dynamic system as well as the several time-domains of the physical phenomenon like rates of the gas-exchange, the consolidation process, the relaxation & creep processes and the applied loading the Langrangian incremental strain has to be used. The insight got by this study will be very helpful to understand practical phenomenon s like soil behaviour during excavation of deep building pits or using vacuum consolidation. Within this scope a number of topics can be defined, like The gas exchange between the free and dissolved gas due to loading and unloading at the level of partial gases, the influence by the gas production due to weathering and the influence of capillary pores on the pore pressure due to the presents of free gas bubbles The interaction between isotropic and shear deformation concerning the triaxial test or oedometer test. The stress relaxation and creep of the solid mass due to isotropic loading condition |
