Investigation of Compressive Strength Characteristics of Hardfill Material and Seismic Stability of Hardfill Dams

A hardfill dam can reduce the natural damage caused by the development of quarries and recycle submerged resources. However, the particle size distribution of the aggregate can result in large variations in the mix design, resulting in a wide range of strengths in the hardfill dam body. Therefore, quality control during construction is crucial, and the stability of the dam body after construction should be thoroughly examined in advance. This study investigated the strength characteristics of hardfill dam materials according to the particle size and mixing ratio through indoor uniaxial compressive strength tests using large specimens and uniaxial compressive strength tests for field compaction and collected cores. Furthermore, the stability of hardfill dams with three types of slopes during earthquakes was evaluated through a finite element analysis. The distributions of stress in the hardfill dam body and the strength required to stabilize the dam body were investigated. Except for a 1:0.6 inclined hardfill dam body to which artificial seismic waves were applied, the overall strength range calculated from the indoor specimens and field compaction cores exceeded the required hardfill strength, thereby ensuring stability in the event of an earthquake.