Abstract: Piezocone penetration tests are widely used to determine the engineering properties of in situ soils. Continuous penetration of the probe in cohesive soils leads to the accumulation of excess pore pressure, which gradually dissipates after the penetration is stopped. In structured silt-clay, clayey silt or silty soils, partially drained may occur during the penetration process, leading to more complex pore pressure dissipation responses following penetration compared to those under undrained conditions. To simulate the entire “penetration-dissipation” process during piezocone penetration and dissipation tests in structured soil, Structured Cam-Clay model is incorporated into the large deformation finite element method within the framework of effective stress analysis. A normalised expression for the dissipation of excess pore pressure after partially drainage or undrained penetration is obtained. The reliability of the large deformation method is verified by comparing with the existing centrifuge tests. A large number of parametric studies have revealed that the effects of soil type, initial soil structure and dissipation depth can be reasonably neglected on the normalised dissipation curve, which can be used to determine the operative consolidation coefficient and subsequently predict the conventional consolidation coefficient.

Key words: cone penetration test, structured soil, finite element, partial drainage, excess pore pressures