Hydraulic failure of granular materials with artificial cementation

Experiments based on hydraulic loading of artificial cemented granular layers by a localized upward water flow revealed the existence of three failure modes: (i) Overall block uplift; (ii) Block rupture by median crack at the inflow zone; (iii) Progressive excavation of a fluidized path along the walls. Despite these distinct scenarios driven by the boundary conditions, the critical flow values at breakpoint are consistent with each other, underlining the local character of the instability, and can be rationalized by extending Archimedes' number to the present case involving adhesion between grains. Agreement is then established with the purely granular case.