Evaluating geoparameters of Maine sensitive clay by CPTU

Abstract

<p>Using two sets of analytical solutions for CPTU in clays, a suite of theoretically-consistent geoparameters is shown to be in good agreement with independent laboratory and field test results obtained on sensitive Presumpscot clay in Portland, Maine, USA. Fall cone tests indicate a mean sensitivity of S<sub>t</sub> ≈ 37. Values of undrained rigidity index (I<sub>R</sub> ), undrained shear strength (s<sub>u</sub> ), and yield stress ratio (YSR) are provided by a modified spherical cavity expansion-critical state hybrid model while an effective stress limit plasticity solution is utilized to assess the effective friction angle of the sensitive clay at both peak strength [ϕ' at q<sub>max</sub> ] and also at maximum obliquity [ϕ' at (σ<sub>1</sub> '/σ<sub>3</sub> ')<sub>max</sub> ]. A CPTU screening method that uses three simplified equations for YSR helps to identify that the clay is sensitive.</p>