Overburden normalization of CPT data in sands to clays

Frameworks for estimating soil properties from CPT penetration resistances must account for the effects of overburden stress on both the penetration resistance and the soil property of interest, including how such effects vary with soil type. For example, common procedures for estimating the liquefaction resistance of sands include functional terms that account for the effect of overburden stress on the penetration resistance (i.e., the CN factor) and cyclic resistance ratio (i.e., the Kσ factor). Common procedures for estimating monotonic and cyclic undrained shear strengths of clays use different notations and functional terms. A single framework for all soil types is a necessary step toward more rational interpretation of properties for intermediate soils. This paper examines the use of a common framework for overburden normalizations of penetration resistance and cyclic resistance ratios in clean sand and ordinary sedimentary clay, with the normalizations cast in terms of either a constant state parameter () or a constant void ratio (e). The examination of these terms for clean sand and ordinary sedimentary clay provides useful bounds for generalization of these frameworks across intermediate soil types. 3 International Symposium on Cone Penetration Testing, Las Vegas, Nevada, USA 2014