Revision as of 12:58, 6 June 2024

Abstract

A recent series of CPTU soundings in sensitive clay at the Louiseville Quebec test site has been published, allowing for the application of two closed-form analytical solutions based on: (1) effective stress limit plasticity and (2) hybrid cavity expansion-critical state methods. These are used for geoparameter interpretations including: effective stress friction angle, undrained shear strength, yield stress ratio, undrained rigidity index, and the coefficient of consolidation. Profiles of these soil parameters are compared with the benchmark values obtained from available series of previous and present laboratory testing programs at this site, including index testing, triaxial compression, and one-dimensional consolidation. Piezocone dissipation tests are used to assess the coefficient of consolidation which are validated by pressuremeter holding tests and lab oedometer tests. An empirical CPTU screening method identifies the Louiseville site as underlain by sensitive clay, versus a regular insensitive clay deposit, whereas soil behavior type charts using Q-F-Bq indicate the soils are either silt (zone 4) or regular clay (zone 3). The alternate screening method is verified by field vane and laboratory fall cone that show the clay is in fact sensitive (average St ≈ 22).

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