Flow behaviour and piping potential at the soil–structure interface

The piping phenomenon that occurs at a soil–structure interface, referred to as backward erosion piping, is often observed beneath hydraulic structures such as conduits buried in levees. In this study, the flow behaviour and piping characteristics at the soil–structure interface were investigated by theoretical analysis using ideal uniform spherical particles and simple experiments. The factors influencing backward erosion piping beneath a structure were evaluated, with the void characteristics of the soil particles and the roughness of the structure surface identified as significant factors that affected the phenomena and the interface flow behaviour.