Interpretation of Piezocone Penetration Tests in Centrifuge

Abstract

This paper presents results of Piezocone Penetration Tests (CPTu) in a sand during the flight of a geotechnical centrifuge at an acceleration of 50 g. Two rates of penetration were used and its effect on penetration resistance was interpreted. Calibration of the CPTu was performed to predict the internal friction angle of the sand using cavity expansion theory and compared with results obtained from laboratory triaxial tests. It is found that penetration rate has strong but different effects on tip resistance and sleeve friction. However, the internal friction angles predicted by cavity expansion theory are approximately identical using a friction ratio to include both the tip resistance and sleeve friction response. It indicates a minor effect of the predicting rate on the soil strength prediction. Further study is needed to clarify the mechanism.