SIMPLIFIED DIRECT BOX SHEAR TEST ON GRANULAR MATERIALS AND ITS APPLICATION TO ROCKFILL MATERIALS

概要

論文の詳細を見る
This paper gives a description of a new"simplified"direct box shear test apparatus in both small and large sizes, and the test results obtained by the new apparatus. In the new apparatus, there is no upper shear box as used in the standard direct box shear test. A loading plate is directly placed on the sample in the lower shear box and pulled horizontally by a flexible rope or chain. By doing this, the effect of frictional forces between the sample and the internal surfaces of the upper shear box induced in the standard direct box shear test during dilatancy is naturally eliminated. The test using the new apparatus is similar to a frictional test on usual materials. A number of tests are performed on glass beads, Toyoura sand and crushed sand using the new small-sized apparatus and on three kinds of granular materials including rockfill materials (the maximum grain size : 150 mm) using the new large-sized apparatus. The test results from the new apparatus agree well with those from standard direct box shear tests in which the effect of frictional forces is reduced, and are near to those from triaxial compression tests. It takes only about 30 minutes to test even the rockfill materials with the new apparatus, including the time to set the specimen.
社団法人地盤工学会の論文
1998-12-15