Sand state parameter from CPT

A cone penetration test (CPT)-based procedure is proposed to determine the in situ density and state parameter ( ψ) of cohesionless soils. To date several correlations have been developed to estimate ψ from CPT results, but most correlations are based on limited calibration testing and/or require soil constitutive parameters from laboratory shear tests. The new framework is based on a limit pressure calculated using cavity expansion theory and a semi closed-form solution that is scaled to existing calibration chamber data using a chamber shape factor. This enables estimation of ψ directly from CPT results, which makes it practical and theoretically sound. This facilitates determining ψ for use in flow failure assessment procedures for dams and embankments.