Study on the evolutionary mechanisms driving deformation damage of dry tailing stack earth–rock dam under short-term extreme rainfall conditions

With the impact of global climate change, dry tailing stack earth–rock dam endures more pressure from short-term extreme rainfall, which is easy to induce dam failure and leads to environmental disasters. In order to further clarify the threat caused by short-term extreme rainfall, taking the actual dry tailings stockpiling as the engineering background, using the research methods of indoor similarity test and numerical simulation, at the same time introducing the technical means of 3D reconstruction based on multi-directional images. The dynamic and high-precision point cloud was obtained, the evolution process of deformation and damage was described in detail, the mechanism and characteristics of disaster occurrence were revealed, and a comprehensive management method was proposed. Research shows that the evolution process of dry tailings rock stack earth–rock dam is divided into four stages: natural state, surface erosion, rill development, and gully and collapse. The dam abutment and dam foot are high-risk areas. The displacement generated by the earth–rock dam gradually spreads from the dam foot to the dam abutment and finally covers the entire outer dam surface; the plastic strain area is always concentrated at the dam foot. The main disaster modes are scouring and erosion disasters, gully and local collapse disasters, and soil erosion disasters. Natural cracks and the structural characteristics of soil particle size also affected the evolution of deformation and failure, as well as the occurrence of disasters. This study has important practical significance for the prediction of geological hazards and the development of disaster prevention and mitigation in tailings dry storage yards.