Infinitesimal-radius penetrometers

With magnitudes of penetration induced pore pressure, p-p available in Equation 1, substituting this relation directly into Equation 5 enables plots of Qi versus 6, to be contoured for permeability, for the case of an infinitesimal radius penetrometer. The resulting relationship is... 

Relations may be developed to represent the steady pore fluid pressures that develop around a penetrometer under steady penetration, at penetration rate, U. These rtKxlels necessarily employ simple linearized constitutive relations, but incorporate the important influence of a porous medium migrating past the penetrometer tip, albeit in a simplified form. Dislocation models (Elsworth, 1991 1993) may be applied to represent a penetrometer of infinitesimal-radius, but suffer the disadvantage that penetration-induced pressures become singular at the assumed penetrometer tip. The approximate solution for a finite radius penetrometer avoids this shortcoming, as explored in the following. 

Figure 2 Contoured plot of B -Q, contoured for Kd for a penetrometer of infinitesimal radius. The conversion between Kd and K is performed for effective stresses at 10 m depth, for penetration of a standard cone at 2 cm/s artdfor A=I.

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