The stilling basin serves as the key flood discharge and energy dissipation structure of high arch dams, which requires regular inspection to guarantee its structural health and stability. Underwater inspection stands as a vital instrument for safety inspection and health diagnosis of underwater structures in water conservancy and hydropower projects. By integrating acoustics, optics, and image recognition technologies, the current study developed the census-detail-refine inspection concept. Accordingly, this study proposed an intelligent inspection method of high arch dams that incorporates multi-beam underwater three-dimensional (3D) sonar detection, unmanned underwater vehicle system, floating-climbing dual-mode underwater inspection, and 3D laser scanning. By using this method, precise water depth data and point information for the target area were acquired. Additionally, high-precision images were generated to depict the attributes of the plunge pond floor. This approach allows for the efficient collection, identification, and health diagnosis of concrete floor defects in complex underwater environments, which effectively overcomes the shortcomings of traditional manual inspection such as high safety risks, limited diving depth, and insufficient detection accuracy. Based on the practical applications in the stilling basin project of Baihetan Hydropower Station, the field results indicate that the detection results of this method are reasonable and reliable. This method helps to further improve the automation, intelligence, and efficiency of underwater inspection operations in hydropower projects, and provides a guide for intelligent inspections of similar underwater hydraulic structures. These results can support the upgrading of inspection technology and the improvement of safety management level in the industry.

Information model is a new collaborative management tool applied to modern engineering design, construction and project management. Based on the problems of incomplete expression of information model and poor circulation of information data during the construction period of water conservancy and hydropower projects, advanced information technology is integrated with the construction process of a super-high arch dam in the context of increasingly frequent iterations and updates of new information technology such as internet of things, big data, block chain and artificial intelligence. The information management system developed here is based on building information modeling (BIM) and information modeling of all the design and construction stages of the super-high arch dam and is used to study information model development and implementation using a modern information model management platform for super-high arch dam construction scheduling, quality and safety and contract using Visual C# network programming technology. The system developed for the 300 m grade Baihetan dam has intelligent management of the entire dam design and construction stages and improved the problems of scattered information and low flow efficiency of hydropower projects in traditional mode, facilitated the control of construction progress and quality, assisted accurate construction and technology optimization, and promoted the development of project management and industry technology.