2003 Volume 43 Issue 1 Pages 1-20
A series of K0-consolidation tests in a triaxial cell was carried out for marine clays collected from different areas in the world in order to investigate the behavior during K0-consolidation tests and evaluate K0-values that are required for laboratory tests with recompression techniques, FEM analysis using elasto-plastic constitutive equations, etc. It was confirmed that the famous equation K0NC = 1-sinφ' is useful; however, the definition of φ' should be concerned. Inthe case using φ' corresponding to a critical state line, i.e. (q/p)max, the equation underestimates K0NC by 0.05 ; in contrast, in the case using φ' corresponding to a peak strength, i.e. (q)max, the equation overestimates K0NC by 0.05. This study proposes a procedure for estimating the in-situ K0-value. For a representative undisturbed clay sample, K0-consolidation and K0-overconsolidation tests (i.e. SHANSEP test) are consecutively carried out to obtain the K-OCR relationship. Using the profile of OCR obtained from a series of oedometer tests, the K-value corresponding to the OCR can be calculated as the in-situ K0. The K0-values obtained from both the K0-overconsolidation test corresponding to the OCR in the laboratory and the flat dilatometer test (DMT test) in the field compared well.