COEFFICIENT OF PERMEABILITY FROM AC ELECTROOSMOSIS EXPERIMENTS .2. RESULTS

Alternating current (AC) electroosmosis tests, which permit rapid dete rmination of the coefficient of permeability of saturated cohesive soi ls are described. The testing device was developed to minimize the adv erse effects of prolonged application of direct current on observed re sponses. The apparatus and procedures to conduct the AC experiments ar e presented and results of 19 experiments are analyzed In these tests, a weak AC is sinusoidally applied under nominally undrained boundary conditions to saturated kaolinite specimens; excess pore pressure and phase angle are measured at frequencies between 0.25 and 4 Hz. The res ults of the experimental program and the procedures of backcalculating the coefficient of permeability are presented. The coefficient of per meability from falling head permeability and AC electrosmosis tests on specimens of resedimented kaolinite are shown to agree within a facto r of five. These data support the theoretical conclusions of the compa nion paper and suggest that this type of test is feasible to rapidly e valuate the coefficient of permeability of saturated cohesive soils in the laboratory.