Research progresses on equipment technologies used in safety inspection, repair, and reinforcement for deepwater dams

China’s many dams are increasingly facing safety problems resulting from the natural aging of the dam hydraulic structure and geological disasters such as earthquakes under the operating condition of holding a vast amount of water. Problems such as dam leakage and concrete cracking and erosion seriously affect the normal operation and effectiveness of a reservior. It is impossible to empty a large reservoir with a high dam for many reasons, such as serious environmental consequences, and it is thus difficult to detect the working conditions of the underwater part of the facility. There is an increasingly urgent demand for detection and repair technologies that can be used in the deepwater environment. Indeed, there are cutting-edge deepwater detection and processing technologies for hidden dangers in dam engineering. The core technologies include underwater detection equipment, diving technologies, and underwater operation technologies. This paper analyzes safety-oriented detection equipment recently used in unmanned detection, manned detection, and deepwater diver detection from the viewpoint of practical application. The paper further reviews 100-m-depth-class technologies and applications of safety inspection, repair, and reinforcement equiment in the deepwater environment of reservoir dams. An outlook is provided on technology trends of deepwater detection, repair, and reinforcement and critical problems.