Investigation of earth dam filter performance under static and dynamic loading conditions

Abstract

Erosion-induced piping is the primary cause of failure in embankment dams’ bodies and foundations. The filter is a principal part of an earth dam, owing to the crucial role of this layer in protecting the clayey core from erosion. Erosion is the process by which soil particles migrate due to an interior fluid flow and is recognized as a significant hazard for earthen constructions. Designing a proper filter-soil system can regulate and seal undesirable cracks that may form in the impermeable core due to nonuniform settlements, extreme water levels, or earthquakes. In this study, a No-Erosion Filter (NEF) test device, which still seems to be the most reliable filtersoil system design, has been adapted to evaluate the performance of the filter sand of two dams under static and dynamic loading conditions. The outcomes were compared with the several filter design criteria in the literature, and it was found that the filter's design approach using the available criteria may not always align with the NEF test results. Therefore, a precise understanding of fluid–particle interactions is necessary to design and operate earth dam filters. The dynamic excitation can change hole pressure distribution and cause erosion even after steady-state conditions under static situations. Consequently, the effectiveness of filters under static conditions does not necessarily translate to satisfactory performance when exposed to dynamic loading.