Cone Penetration Resistance in Coarse-Grained Gravelly Soils
Alexander P. Pires-Sturm, Jason T. DeJong
Abstract
Centrifuge testing data are presented to elucidate the influence of particle size and gradation on cone penetration resistance. The physical, index, and material properties of nine test soil mixtures, sharing a common geologic origin and ranging in D50 from 0.18 to 2.58 mm and Cu from 1.53 to 9.86, were quantified and compared to the range of values exhibited by clean sands in the literature. Each centrifuge model was subjected to dynamic loading and characterized by six cone penetration test (CPT) soundings performed at DR values ranging from 23% to 96%. The coarser soils exhibited higher cone penetration resistances than clean sands under comparable conditions due to the continuum failure mechanism becoming compromised (more likely as DCPT/D85 decreased) and the variation in mechanical properties with particle size (e.g., G and ϕpk′). This study provides insight into the multifaceted influence of soil gradation on penetration resistance, which can be leveraged in engineering practice to improve the in situ characterization of coarse-grained gravelly soils.