There is a lack of safety and emergency management system and mechanism for cascade hydropower stations in China. To prevent and respond to safety emergencies of dams in the upper reach of Yellow River basin, and to control, mitigate and eliminate adverse effects of emergencies, study on the safety and emergency management of 13 hydropower stations in the reach from Longyang George to Liujia George was carried out by State Power Investment Group Huanghe Hydropower Development Company Limited. The analysis of risk classification matrix and the theory of risk prevention were used to establish the dam safety and emergency management mechanism suitable for hydropower stations in the upper reach of Yellow River belonging to different owners. The study results were of great importance and worthy reference.

This paper collected and reorganized the calculation results of dam-breach flow of some hydropower stations in the power industry, and summarized and analyzed the current status of dam-breach flow calculation from the aspects of calculation methods and breach shape. The results showed that there were some problems in dam-breach flood analysis, such as improper selection of calculation methods and random assumption of dam breach shape. The suggestions provided in this paper could be used as a reference for dam breach analysis and research in similar projects.

Water conservancy and hydropower projects have the characteristics of long construction period, complex structure, and being greatly affected by natural factors. An accidental factor in operation may sometimes lead to systematic safety accidents of the whole hydropower station. The author summarizes some typical cases of domestic hydropower station accidents in recent years, and analyzes some risk factors needing attention in the construction and operation management of hydropower stations, to provide reference for design, construction and operation management.

After the reinforcement of Longshan reservoir, there is a problem of settlement, which leads to cracks on the dam crest and has unknown impact on the dam operation safety. This study comprehensively uses pit exploration, drilling and geophysical exploration methods to evaluate the dam operation safety, analyze the current situation of dam filling, investigate and analyze the causes of cracks and settlement problems. Meanwhile, the impact of the infiltration line lowering caused by reinforcement is considered to conduct a preliminary evaluation of settlement. The results indicate that the settlement of Longshan reservoir is mainly due to the low filling quality in some areas of dam body and the infiltration line lowering, which leads to the consolidation settlement of filling material. Although the settlement situation still meets requirements, the risk of continued settlement cannot be ruled out. It is necessary to excavate the non- dense soil and rerun the thickening and reinforcement project. The relevant survey methods and analysis can provide reference for similar dam settlement problems.

Based on design review, the typical problems in design of safety monitoring for small reservoirs were systematically summarized, including inadequate capability of design organization, omission of important design content, incomplete design-related basic information, improper utilization of existing safety monitoring equipment, design divorced from engineering practice, confusing set of important and unimportant monitoring items, and et al. It is proposed that the quality management of safety monitoring needs to be enhanced in aspects such as more attention paid to the design, improvement of guidance and training, strengthening of design inspection, special focus on safety monitoring design of reinforced and newly-built small reservoirs.

The“1·12”water inrush accident of Guanzhou hydropower station reflects the problems that the main responsibility of safety management is not implemented, the procedures of bidding and procurement are chaotic, and the quality of pipe bulkhead is poor. Enterprises in charge of the operation and management of hydropower stations should learn from this accident. In order to eliminate risk factors and ensure the operation safety of power stations, responsibilities of relevant departments should be fulfilled, technical management should be strengthened, and the sensitivity and responsibility of operation management personnel should be improved.

In recent years, a large number of pumped storage power stations have been built in China, and the reservoir engineering geological conditions determine the feasibility of the construction. Through on-site geological surveys and tests, the leakage and bank slope stability of the proposed upper reservoir are evaluated. Research has shown that the project is located in an area with prominent leakage problems. It is recommended to deal with the problems of dam foundation leakage and seepage around dam during the anti-seepage of upper reservoir basin. The engineering slope is generally stable. For the broken rock body affected by faults, as well as disadvantage blocks formed by the cutting and combination of faults, interlayer joints and dominant joints, the effective support measures should be taken in time according to the excavation exposing situation.

With the development of information technology, the traditional paper-based hydraulic patrol inspection work is gradually transformed into a patrol inspection management system (module). At present, the patrol inspection system still has some problems. For example, the patrol inspection objects are not abstractly classified, the defects are not objectified, and the functions of patrol inspection App are simple. Aiming at the above-mentioned problems, the optimization design scheme is proposed and applied to the patrol inspection module in the dam safety information management system for Yalong river basin. Web terminal and mobile terminal (App) are mainly included in this module and functions such as viewing tasks, patrol inspection, result recording and query, defect tracking and query are available. With the help of information management means, this system can optimize the information management mode of hydraulic patrol inspection and further improve the level of dam safety information management.

Multi-point displacement meters are widely used in deformation and displacement monitoring of slope rock mass and cavern rock of water conservancy and hydropower projects, which can realize automatic monitoring and safety warning. The new multi-point displacement meter device introduced in this article is a new structural type different from the old described in DL/T 1272—2013, including an anchor head, a transmission rod (steel pipe) and a plastic protection tube installed with concentric shafts, as well as the orifice mounting base and the matching displacement sensor. Its application range and measurement accuracy are exactly the same as the multi-point displacement meter device, and its technical performance is superior. It has advantages such as high equipment precision, easy installation and high observation accuracy. Moreover, one of its important technical achievements is realization of the dual functions of manual instrument measurement and automatic measurement by displacement sensor, which can be used to verify the automated measurements and realize the continuous observation by use of the manual measurement data during replacement of the displacement sensors.

The diversion tunnels of Jinping Ⅱ hydropower station extend across Jinping mountain, including the areas with high stress and high external water pressure. The tunnel section is huge. In order to ensure the long-term and safe operation of the power station, the maintenance channels are arranged for diversion tunnels. This paper introduces the design and structural calculation of the maintenance shaft of emergency gate in water inlet and the access door of construction adit at the head and end of the diversion tunnel.

Dams have the life cycle of“birth, aging, illness and death”like human beings. Based on the human health examination mode, and taking concrete dams as the object, this paper discusses the corresponding relationship between dam health diagnosis and human health examination. The analysis shows that the dam field inspection and human physical examination are similar in function, the dam safety detection is similar to human chest X-ray, B-scan and laboratory examination, and the dam safety monitoring is similar to medical health monitoring methods such as human health bracelet and monitoring chip implantation. Therefore, based on the above discussion, the authors put forward some suggestions about the dam health diagnosis mode based on“inspection, detection and monitoring”integration and multi-source information fusion.