Large-scale three-dimensional experimental investigation on potential high position landslide‑induced waves in Gushui Reservoir, China

Abstract

Abstract The occurrence of landslides in reservoir areas and the potential secondary disasters near dams are characterized by their sudden and catastrophic nature, often limiting the availability of actual measurement data. To address this challenge, prototype physical model test always proves to be valuable method to replicate or reproduce such geological hazards. In this study, we focused on the Meilishi landslide in the Gushui reservoir area as a case study to analyze the potential threat of high position landslide-induced waves under gravity. Based on field investigations and relevant statistical geological data, a large-scale three-dimensional physical model was carried out that integrated the interactions of the landslide, the river, and the dam. With a scale of 1:150, the model had the dimensions of 57, 27, and 8 m. Water level and the maximum sliding velocity into the water were selected as independent variables, leading to a total of 18 experiments. An adaptive landslide motion simulation system based on velocity equivalence and a comprehensive measurement system with tracking technology based on hydrodynamics were independently developed. Those approaches allowed us to reveal the propagation characteristics and attenuation laws of high position landslide-induced waves in a curved channel under various complex conditions. The data showed that the maximum wave run-up height on dam was 17.97 m under the most dangerous working condition (H3C09). Importantly, this value did not exceed the maximum height of dam, indicating a certain level of safety margin for the dam. Combined with the data of different working conditions, the optimal window for landslide risk prevention and control warnings was within 550 s after the onset of landslide instability. The key parameters predicted by the tests, including head wave height, wave run-up height on the opposite bank, wave run-up height on dam, and the propagation times, provided a technical basis and valuable reference for dam engineering design and safety. These results make significant contributions to the prevention and control of similar surges hazard induced by high position landslides around the world.