Calibration of hybrid SCE-CSSM analytical model for piezocone penetration in clays

Fawad S. Niazi, Paul W. Mayne, David J. Woeller

In the proceedings of: GEO2011: 64th Canadian Geotechnical Conference, 14th Pan-American Conference on Soil Mechanics and Geotechnical Engineering, 5th Pan-American Conference on Teaching and Learning of Geotechnical Engineering

Session: In Situ Testing

ABSTRACT: Piezocone penetration test (CPTu) readings of total tip resistance (qt), corrected sleeve friction (fst), and shoulder porewater pressure (u2) in fine-grained soils can be modeled using spherical cavity expansion (SCE) theory and critical state soil mechanics (CSSM) concepts. The predicted profiles can be fitted to the measured CPTu response using input of soil parameters: preconsolidation stress (p'), total unit weight (t), effective friction angle ('), rigidity index (IR), and compressibility parameters (Cc and Cs). This paper presents application of such a formulation for CPTu representation obtainable using a hybrid SCE-CSSM model to a variety of clays sites which have been field tested by CPTu. These deposits have known profiles of t, ', p' and compressibility parameters determined from laboratory tests, and shear stiffness (Gmax) obtained from field measurement of shear wave velocity (Vs). Undrained shear strength (su) evaluated via critical-state concepts are used together with Gmax to evaluate IR over a range of applicable strains.

RÉSUMÉ: (SCE) et des concepts de mécanique des sols aux états critiques (CCSM). Les profils modélisés peuvent être comparés aux lectures prisent par le piézocône en utilisant les propriétés du sol telles que la contrainte de -CSSM essais de laboratoire. Les valeurs de rigidité ont été obtenues aussi sur le terrain par des essais au piézocône sismique. Les résistances au cisaillement en condition non drainée ont été évaluées par la théorie des états critiques et la valeur du module pour évaluer le paramètre de rigidité Ir pour une vaste étendue de niveau de déformation.

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Cite this article:
Fawad S. Niazi; Paul W. Mayne; David J. Woeller (2011) Calibration of hybrid SCE-CSSM analytical model for piezocone penetration in clays in GEO2011. Ottawa, Ontario: Canadian Geotechnical Society.

@article{GEO11Paper409,author = Fawad S. Niazi; Paul W. Mayne; David J. Woeller ,title = Calibration of hybrid SCE-CSSM analytical model for piezocone penetration in clays,year = 2011}