A Biaxial Consolidation Test for Anisotropic Soils

A biaxial flow consolidation test was developed to determine the axial and radical permeabilities, k_a and k_r, respectively, of a transversely isotropic specimen. The test enables the additional information needed to determine the ratio of permeabilities, k_a/k_r, to be obtained by independently measuring the flow from the specimen ends and circumference during consolidation. By comparing the ratio of flows from the specimen ends and circumference to the theoretical relationship, the ratio of permeabilities can be determined. The radial permeability, , to be obtained by independently measuring the flow from the specimen ends and circumference during consolidation. By comparing the ratio of flows from the specimen ends and circumference to the theoretical relationship, the ratio of permeabilities can be determined. The radial permeability, k_r, is determined from the total time rate of consolidation.

Comparisons between various methods of permeability measurement and the proposed test are shown to be good. From the theoretical development, it was found that anisotropy in stiffness can have an important influence on test results. A method is presented for determining relevant stiffness parameters by combining the strain measured during consolidation and pore-pressure response.