Indentation of a Sharp Penetrometer in a Poroelastic Medium

Solution is developed for the build!up\ steady and post!arrest dissipative pore ~uid pressure _elds that develop around a conical penetrometer advanced in a poroelastic medium[ The analog with cone penetrometer testing is direct\ and is used to enable continuous distributions of permeability and di}usivity to be determined\ with depth[ Solution for a point normal dislocation migrating in a poroelastic medium is extended to incorporate the in~uence of a tapered tip[ Steady pressures develop relative to the migrating tip geometry with distribution conditioned by the non!dimensional penetration rate\ UD\ incorporating penetration rate\ hydraulic di}usivity and penetrometer radius[ The near!spherical pressure distribution\ recovered for low penetration velocit! ies\ becomes radial as penetration rate increases[ Along the penetrometer shaft\ non!dimensional induced pore ~uid pressures\ PD\ are independent of penetration rate\ UD\ and asymptote to an inverse radial distribution remote from the tip as PD 0:xD[ This importantly identi_es the control on penetration induced pore ~uid pressure as the magnitude of permeability\ embodied in the non! dimensional pressure\ PD\ rather than a dependence on hydraulic di}usivity\ as had previously been considered[ Induced pore pressures are singular in the zone of tip taper for the assumed zero radius of the penetrometer\ negating the direct evaluation of permeability magnitudes from pressures recorded on the cone face[ However\ the _nite magnitudes of ~uid pressures evaluated on the shaft may be correlated with _eld data to independently evaluate magnitudes of permeability during steady penetration[ Þ 0887 Published by Elsevier Science Ltd[ All rights reserved[