Experimental analysis of heaving phenomena in sandy soils

Seepage erosion phenomena can arise when particles of soil are transported underneath any hydraulic structure by the seepage flow, as a consequence of the difference in the surface elevation upstream and downstream of the hydraulic structure. To assess the stability of hydraulic structures against seepage erosion computational models are available varying from simple empirical rules to advanced models. In this paper, the safety coefficient is assessed by comparing the exit gradient with the critical gradient: the former represents the hydraulic gradient at the exit point along the downstream ground surface, whereas the latter is the gradient at which upward drag forces on the soil particles equal the submerged weight of the soil particles and a quicksand condition originates. An experimental research was carried out to analyze different thickness sheet piles embedded in sandy soils, resulting in agreement between experimental data and theoretical values if the thickness of the sheet pile and the ground surface deformation are properly taken into account.