A simplified method for assessment of volume change behavior of rockfill material

In this paper an attempt was made to generalize the results of laboratory tests on modeled rockfill materials so as to evolve a simplified method for assessment of their hulk mechanical properties from minimum test data with an acceptable degree of confidence. Examination of the experimental data of the modeled rockfill materials from different sites revealed that the plots of logarithm of strain at failure against logarithm of confining pressure are linear. A trend of increase in failure strain with increase in confining pressure and maximum size of particle is also observed. The simplified approach highlights prediction of volume change properties of rockfill materials during isotropic consolidation and triaxial state of stress over a range of confining pressures and particle sizes. This approach is based on the results of only two tests carried out at two different confining pressures for a selected maximum particle size on modeled rockfill material with the use of the parallel gradation technique. The two-test approach and its application in engineering design of rockfill materials is illustrated by means of selected experimental data available in the literature