Theoretical Formulation of Piping Mechanism in Cohesive Soils

Synopsis A theory is presented for piping mechanism in cohesive soils which is also applicable to cohesionless soils. Taken into consideration are the various forces acting on a soil element, namely the drag force due to water flow, the submerged weight and the soil tensile strength. The theory explains the high resistance of cohesive soils to piping. It was found that the safety factor against piping in a cohesive soil is inversely proportional to the size of the aggregate that may be washed out. An assessment of the size of aggregate is made possible by the theory developed. Experimental results are presented and correlated with the theory. Cet article presente une theorie sur le mecanisme de canalisation pour les sols coherents. Il est tenu compte des forces diverses agissant sur un element de sol, a savoir la force de resistance due a l'ecoulement de l'eau, le poids submerge et la resistance a la traction du sol. La theorie explique la grande resistance des sols coherents au transport par canalisation...