Comparative tests for evaluating permeability changes of a compacted bentonite/sand mixture during shear

Comparative test on bentonite-sand and kaolin-sand mixtures were conducted using a recently-developed coupled shear and permeability testing apparatus under temperature controlled conditions. The specific storage of bentonite-sand specimen during shear was evaluated using the analytical theory for the constant flow permeability test. Controlled temperature was preferred in the measurement of the permeability of extremely-low permeability materials with the constant-flow pump method. The permeability and specific storage of the mixture of Kunigeru VI bentonite and D-sand were not influenced by shear strain while the kaolin-sand mixture increased with the increment of shear strain.