ESTIMATION ON COEFFICIENT OF CONSOLIDATION AND PERMEABILITY DURING DEHYDRATION OF DREDGED CLAY

Authors have been developing a technique to make high-strength soil concrete block using high-pressure dehydration apparatus with a radial drainage system. Constant strain rate consolidation tests were conducted for solidified treated soil mixed with dredged clay and blast furnace slag cement class B (BB) for clarifying the relationships between consolidation pressure p and coefficient of consolidation cv/ permeability k. In addition, permeability k of the materials were estimated from exchangeable capacity of cations measured before and after the consolidation tests. Coefficient of consolidation cv during block manufacturing tests were estimated by parametrically calculating time and settlement curves using radial drainage theory. Following results were obtained from this study. (1) when estimating k using ion exchange capacity, it was found necessary to take into account changes over time in specific surface area due to pore structure and solidification. (2) it was suggested that a cv greater than 1 MPa of working pressure in the constant-strain consolidation test should be used to estimate the cv of the block.