Mercury intrusion and permeability of Louiseville clay

Several theories have been proposed to correlate the permeability (hydraulic conductivity) with the pore-size distribution of soils, and it seemed interesting to determine if these theories could be applied to natural clays. For this purpose permeability and mercury-intrusion porosimetry tests were performed on a Champlain Sea clay for both intact and remoulded conditions after compression of the specimens to strains varying from 0 to 42%. The results show that for either intact or remoulded soil conditions, there is a relationship between the pore-size parameters and the permeability of the clay. However, there is no unique relationship for both intact and remoulded clays and for the silt and clay considered in previous studies. Consequently, mercury-intrusion porosimetry alone cannot be used to evaluate the permeability of soils in general. Key words: permeability, clays, mercury-intrusion porosimetry, fabric.