Evaluating geoparameters of Maine sensitive clay by CPTU

Abstract

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 St ≈ 37. Values of undrained rigidity index (IR), undrained shear strength (su), 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 qmax] and also at maximum obliquity [ϕ′ at (σ1′/σ3′)max]. A CPTU screening method that uses three simplified equations for YSR helps to identify that the clay is sensitive.