Evaluation of mechanical properties of sand loosened due to piping

摘要

Piping, known as a complex phenomenon of internal erosion, presents a great risk for hydraulicrnstructures. In this research, artificial piping in laboratory was created by dissolving glucose column in uniformrnfine (Toyoura) sand. Properties of loosened sand due to piping effect were studied through a series of triaxialrntests under different densities, pipe number and confining pressure. Piping propagation was observed accordingrnto the axial strain, radial strain and volumetric strain measured by local transducers. Furthermore, Young’srnmodulus and Poisson’s ratio of sand with internal pipes were also evaluated under cyclic loading before and afterrnloosening.