INTEGRATED SHEAR AND FLOW PARAMETER MEASUREMENT

Studies on the variation of permeability and the specific storage of b entonite-sand mixtures with shear deformations that may be caused by e arthquakes and/or other geological events are of fundamental importanc e for long-term safety assessments of radioactive nuclear waste dispos al facilities. This paper presents a recently developed and improved m ethod for integrated shear and flow parameter measurements on a mixtur e of Kunigeru V1 Bentonite and D-Sand. This material will be used in l ow-level radioactive nuclear waste disposal facilities in Japan. The r esults of this study show that: (I) temperature control is important f or measuring hydraulic parameters of low-permeability materials with t he flow pump method; (2) shear strains up to about 3% did not signific antly influence either the permeability or the specific storage of the bentonite-sand mixture; and (3) permeability and specific storage val ues interpreted from different time intervals during the transient ris e and transient decay phases of the flow pump permeability tests were almost the same, which suggests that the reliability of both the exper imental results and the newly derived theoretical analysis used to int erpret the hydraulic parameters.