Representative consolidation coefficient values in Hong Kong soils

The traditional method of determining the coefficient of consolidation in Hong Kong soils is to use oedometer testing. However, this gives unrealistically low coefficients for more permeable soils, resulting in over-conservative foundation designs. To extend the determination to more permeable materials, test results from isotropic consolidation in a triaxial cell can be adopted. Building on a previous study into marine clay and decomposed granite, the study reported in this paper covered most major soil types in Hong Kong to provide designers with realistic values for consolidation coefficients. First, a new method was developed for processing the large volume of soil data collected. This made it possible to conduct a detailed examination from fundamental soil behaviour of how consolidation coefficients are affected by parameters such as soil type, in situ dry density, particle size distribution, testing type and testing laboratory.