Consolidation properties of soil slurries from hydraulic consolidation test
Finite strain consolidation theory is commonly used for the initial design and later reclamation of disposal facilities for highly compressible waste materials such as phosphatic clays, dredgings, and mine tailings. An alternative technique is presented for performing a hydraulic consolidation test to measure the required compressibility and hydraulic conductivity constitutive relationships of such materials. Closed-form equations are derived for the discharge velocity and the distribution of total head, pore pressure, and effective stress at steady flow conditions for a hydraulic consolidation test. A two-stage test procedure is described in which the specimen height and discharge velocity are measured for two successive hydraulic gradients. At the conclusion of the second stage, the distribution of local void ratio is obtained by slicing the specimen. Analysis of the test results has advantages in comparison to other available approaches because specialized numerical procedures are not required to calculate the desired constitutive relationships for a soil specimen. Theoretical predictions from the model are in close agreement with experimental measurements for hydraulic consolidation tests of two clay slurries.