Published online by Cambridge University Press: 28 February 2011
To predict the mechanical performance of earthen backfill in a nuclear fuel waste disposal vault, the effects of temperature and moisture content on the backfill load-deformation characteristics must be known. Modified California Bearing Ratio (CBR) tests were used to obtain these data. The results show that the load-bearing capability of the backfill is not likely affected by water salinity. The load-bearing capability decreases with increasing temperature and water content or decreasing dry density. The effects of temperature, dry density, and moisture transport processes on load-bearing capability were found to be relatively small compared to those of moisture content. Under the expected Canadian vault environment, the backfill should retain sufficient bearing capacity to satisfy its mechanical design function, which is principally to limit expansion of swelling buffer material.