The Second James K. Mitchell Lecture Undisturbed sand strength from seismic cone tests

Abstract

During routine site investigations, high-quality sampling and laboratory testing of sands are not feasible because of inevitable sample disturbance effects and budgetary constraints. Herein, a select database is compiled for calibration of cone penetration test (CPT) interpretative methods, primarily from undisturbed frozen sand samples at 15 sites in Japan, Canada, Italy, Norway, and China. The database is used to evaluate the peak secant friction angle in terms of the normalized cone tip resistance using two analytical approaches: (i) spherical cavity expansion theory with an operational rigidity index , and (ii) a limit plasticity formulation with appropriate angle of plastification . Backfigured values of and are found correlated to the normalized small-strain stiffness . Thus, with measurements taken of both the initial shear modulus and shear strength, seismic cone tests offer the opportunity to derive the entire stress–strain–strength response of sands at all depths.

Keywords:

• Sand
• Seismic cone tests
• Stress–strain–strength response
• Cone penetration test
• Calibration
• Frozen sand

Acknowledgements

The author thanks the National Science Foundation (Award CMS-0338445) and the Mid-America Earthquake Center (Award EEC-9701785) for their support. Any opinions, findings, and conclusions or recommendations expressed here are those of the author and do not necessarily reflect those of the NSF or MAE.