Associate professor of civil engineering, Wayne State University, Detroit, MI
Civil engineer, Army Corps of Engineers, Nashville District, Nashville, TN
A nonlinear theory of consolidation under linear loading is formulated for various load-increment ratios. Variable coefficients of permeability and volume decrease and constant coefficient of consolidation are assumed during consolidation. The results obtained for a very small load-increment ratio very closely follow those of Schiffman's linear loading theory. A hydraulic loading odometer having provisions for applying linear loading and multipoint pore-pressure measurement is developed. Laboratory linear loading tests on kaolin and Calcuttta silty clay under a load-increment ratio K of 0.25 indicate that the experimental pore pressures dissipate at a faster rate than predicted by both non-linear and Schiffman theories. Improved agreement between experiment and theories are observed for K = 4. A quasi-preconsolidation effect is observed during early stages of consolidation. The void ratio effective stress relationship based on base pore pressures and isochrones obtained during slow rate of linear loading tests very closely follows the curve determined conventionally.
Paper ID: JTE11063J