A method for in-situ testing of coefficients of consolidation and permeability of soils

Coefficients of consolidation and permeability are key parameters in the calculation and design of foundations. IFCO BAT-System was used to estimate coefficients of consolidation and permeability for soils in this study.Theorie s of cylindric al cavity expansion with different pore-pressure parameters inside and outside of the p lastic zone and one-dimensional consolidation, were applied to simulate distrib ut ion and dissipation of initial excess pore pressure around the filter tip. Flow characteristics of needle and water columns of filter tip and container were bot h considered in the analysis of coefficient of permeability.The comparison sho ws t hat in-situ results are close to laboratory values of samples taken with thin-wall sampler. In addi tion, the cause for the difference between in-situ results and laboratory valu es and its rationality were discussed.