CONSOLIDATION OF CLAY BY SAND DRAIN UNDER TIME-DEPENDENT LOADING

The mathematical theory and physical laws of one-dimensional consolida tion of clayey soils are well-known. Sand drains accelerate the consol idation process. Several analytical and experimental studies have alre ady reported on sand drain consolidation of clayey soils. However, the literature does not contain a nonlinear theory of sand drain consolid ation under time-dependent loading that can take into account any effe ctive stress/void ratio/permeability variations. A generalized governi ng equation, capable of yielding a large class of analytical solutions for these variations is derived in this paper. Closed-form solutions are presented for the variation of pore water pressure with a time fac tor and load increment ratio under time-dependent loading. The analyti cal formulation is validated by comparing the solution with the standa rd results available in the literature for instantaneous loading, cons tant permeability, and constant compressibility.