Expansion curves define the increment in permeability with increasing mean effective stress, and compression curves define reduction in permeability with increasing mean effective stress in the reservoir zone.
Soft rock type means that the formation is highly stress sensitive and permeability variations will be significant based on the mean effective stress in each reservoir zone.
The results show that the elastic shear modulus value is mainly dependent on the value of the mean effective stress and relative density.
The widely used mean effective stress parameter is modified to include the influence of cementation on the strength and the plastic deformation of cemented clay.
This extension uses stress-dependent Lamé parameters instead of fixed values: a mean effective stress-dependent compressibility modulus C and a shear stress-dependent inverted shear modulus, D τ2)=1/G(τ2).
Curves showing decay of the pore fluid pressure with time, the corresponding change in mean effective stress and the variation of displacement, are plotted in non-dimensional form.
The coefficient for the permeability modification of the rock is assumed to be a function of the mean effective stress via a hyperbolic tangent function.
Since the soil during the experiment was not subjected to any confinement, therefore, the shear modulus for numerical analysis has been estimated for a very low mean effective stress of 1.0 kPa.
These results underscore the importance of excess pore water pressure in reducing the ultimate pile capacity by reducing the mean effective stress during shearing at the pile-soil interface level.
It is shown that the small-strain shear moduli of sands under anisotropic loading conditions are greater in magnitude than those subjected to isotropic stress states at a given mean effective stress.
