A SIMPLIFIED METHOD FOR ASSESSMENT OF VOLUME CHANGE BEHAVIOR OF ROCKFILL MATERIAL

In this paper an attempt was made to generalize the results of laborat ory tests on modeled rockfill materials so as to evolve a simplified m ethod 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 sit es revealed that the plots of logarithm of strain at failure against l ogarithm of confining pressure are linear. A trend of increase in fail ure strain with increase in confining pressure and maximum size of par ticle is also observed. The simplified approach highlights prediction of volume change properties of rockfill materials during isotropic con solidation and triaxial state of stress over a range of confining pres sures and particle sizes. This approach is based on the results of onl y two tests carried out at two different confining pressures for a sel ected maximum particle size on modeled rockfill material with the use of the parallel gradation technique. The two-test approach and its app lication in engineering design of rockfill materials is illustrated by means of selected experimental data available in the literature.