Swelling-Pressure and Hydraulic Conductivity of Compacted Clays Focusing on the Clay-Mineral Type

It is very important to notice clay minerals, for resource development, stability evaluation of underground utilization, and others. However, few quantitative data on the effects of clay-mineral type on the swelling characteristics and permeability of clays and clay minerals have been reported to date. This study was conducted to investigate the effects of clay-mineral type on the swelling characteristics and permeability of compacted clays using one-dimensional swelling-pressure and constant-pressure permeability tests. Comparative tests revealed that the difference of clay-mineral type in the clays influences the swelling-pressure and hydraulic conductivity. The swelling-pressure and hydraulic conductivity were closely associated with the specific surface area of clays. Furthermore, hydraulic conductivity was almost consistent that measured with the Kozeny-Carman equation. This result suggests that hydraulic conductivity can be estimated based on a specific surface area and void ratio of compacted clays.