Regina clay has long been known for exhibiting swelling properties, causing the distress and damage to civil infrastructures. The expansive nature of the Regina clay deposit along with severe climatic conditions is primarily responsible for the observed volume change tribulations. For a selected site with high frequency of reported infrastructure deterioration, the geotechnical index properties were determined. The results indicated that the soil profile has three distinct layers: a topsoil (from surface to 0.3 m depth), an expansive clay (from 0.3 m to 8 m), and a bottom till (from 8 m to 9 m). The cumulative heave was found to range between 70 mm and 120 mm along with an active depth of 2.8 m to 4.6 m. The analysis into clay allowed to divide this unit into: (a) fissured clay, and (ii) intact clay. The fissured clay samples were found to possess low air entry values (AEV's) for fissured portions ranging from 0.2 kPa to 0.4 kPa and high AEV's for intact portions from 209 kPa to 437 kPa, while the intact clay samples exhibited high AEV's varying between 151 kPa and 492 kPa. The high AEV's corresponding to the intact portions of the fissured and intact samples represented high water retention capacity of the expansive clay. The field suction (psif) values generally varied in the range of 102 kPa to 103 kPa. The unsaturated hydraulic conductivity functions (kunsat ) for the soil profile had wide range of variations that is; by twelve orders of magnitude (from 10-3 to 10-15 m/s) for field volumetric water content (thetaf) and field suction (psif). This study analysed the swelling properties and saturated-unsaturated soil properties of the local expansive soil deposit.
展开▼
