Author(s): Byunguk Kim; Jeong Won; Yong Sung Park; Il Won Seo
Linked Author(s): Il Won Seo, Byunguk Kim
Keywords: Backward erosion piping; Tracer test; Tracer residence time; Hydraulic gradient
Abstract: Embankment failures is often attributed to internal erosion beneath the embedded structure, with backward erosion piping being the most representative type. Water level difference between upstream and downstream of embankment induces seepage flow, resulting in soil particles being eroded. The erosion mostly starts from the exit of the seepage flow, and it grows through the preferential flow path, forming pipe-shape waterway. Thus, since the widening of that waterway can potentially lead to structural collapse, preventing the backward erosion piping process is required. However, such underground phenomenon at the site is difficult to be detected due to the poor accessibility. This study fabricated an apparatus to investigate the backward erosion piping with different hydraulic gradient, bed materials, and presence of cutoff wall. In addition, tracer test is also implemented to indirectly grasp the seepage flow through the void of sediment bottom. The goal of this study is to identify the relationship of the piping progression to breakthrough curve of tracer concentration, and to propose a method to detect the piping occurrence using the tracer test.
Year: 2024