Stress History of Soils from Cone Penetration Tests

Stress history is an important measurement in soils as it affects strength, stability, stiffness, and flow characteristics. The evaluation of the in-situ preconsolidation stress, or effective yield stress, from the results of piezocone penetration tests allows for an economical and expedient means to profile the stress history of clays, sands, and mixed soil types on geotechnical projects. The methodology is based on a derived analytical cavity expansion critical state solution for clays and statistical inversion of data from calibration chamber tests on sands. Applications are given for case studies involving clay, silt, and sand where laboratory consolidation tests provide benchmark values for the stress history. Since yield stress demarcates contractive vs. dilative soil behavior, extended uses in screening soil susceptibility for concerns involving flow and cyclic liquefaction are also presented.