Experimental investigation on the erodibility and slaking of glacial till

This study investigates glacial till erosion and the impact of slaking—soil disintegration upon water immersion—critical for projects like the Lake St. Martin Outlet Channel in Manitoba, Canada. Using a hydraulic flume, 48 erosion tests on intact glacial till revealed that non-slaked till consistently exhibited critical shear stress exceeding 13 Pa, often beyond the 17 Pa limit of the apparatus. In contrast, slaked till had a critical shear stress below 2 Pa, indicating significantly higher erodibility. The slaking threshold, determined by drying samples to increasing matric suction levels before immersion, ranged from 4 to 400 Pa, depending on sample density and clay content. Slowly saturated samples showed no slaking, while lime stabilization effectively mitigated slaking, suggesting it as a viable erosion control method. These findings enhance understanding of glacial till behavior and support improved infrastructure design and management in flood control projects.