2018 Volume 24 Pages 607-612
River levees built on permeable foundation ground have risk of levee breach accompany with piping development, so it is important to have reliable evaluation detecting progression from a sand boil to a levee breach. In this study, we used a model experiment to evaluate channel development, and as a precondition of the foundation ground, a water channel was likely to develop in the horizontal direction. Using a seepage analysis which modeled channel development in foundation, we were able to reproduce reduction of the pore pressure accompany with channel progression in the foundation. Occurrence and discontinuation of channels showed the possibility of being evaluated by comparing the actual velocity calculated with the elements equivalent to the deformation size at the boundary between foundation and levee body with the critical velocity.
