Design and analysis of shaft spillway under complex topographic and geological conditions

The layout of flood discharge structures in reservoirs is difficult under complex terrain and geological conditions.To ensure both the safety and cost-effectiveness of the project, this study took Asanduo Reservoir in Diqing Prefecture, Yunnan Province as a case study.In response to its complex terrain and geological conditions, small discharge capacity, relatively high dam height, and significant upstream-downstream elevation difference, a more rational shaft-type diversion spillway tunnel scheme was proposed.The feasibility of the proposed scheme was verified through hydraulic model tests.The results indicated that compared with traditional open-channel spillway scheme, the shaft-type scheme could better adapt to the site-specific challenges of high elevation differences and steep slopes by adapting to local conditions.This approach effectively reduced construction complexity and improved the overall technical and economic performance of the project.The research results can provide references for similar projects.