68th Canadian Geotechnical Conference and 7th Canadian Permafrost Conference

SHORT AND LONG TERM COMPRESSIBILITY OF ROCK PARTICLE ASSEMBLAGES

Session: Embankments and Dams / Remblais et barrages

Vincent Cormier, Université Laval / WSP (Canada)
Jean-Marie Konrad, Université Laval (Canada)

During construction and first impoundment of rockfill dams, significant deformations can occur due to crushing of highly stressed rock particles. In order to improve the general understanding of this phenomenon, short term and long term compressibility of assemblages of rock particles was studied with one-dimensional compression tests in a large oedometer cell. The main results from the test program revealed that short term compressibility tends to be more important for samples with a wide grain size distribution curve, a low density and when the samples were wetted or saturated prior to loading. With respect to long term compressibility, it appears that the ratio between the time-dependent compressibility index and the compressibility index, Ce,t/Ce,s, tends toward a constant of about 0.02 for dry rock particles and 0.03 for saturated samples. Furthermore, the compressibility was successfully related to a breakage factor, highlighting the importance of particle breakage on deformations of rockfill.