Earthquakes, especially strong earthquakes, may easily cause dam accidents. The actual damage of the dam is determined by the earthquake intensity, which is related to the earthquake magnitude, hypocenter depth, geological structure and the distance between the dam and the hypocenter. To realize the graded warning for dams under the condition of earthquake, it is necessary to use the statistical model to quickly calculate the earthquake magnitude at the dam site and compare it with the design standard. By computer programming, the above-mentioned functions can be realized, which can quickly locate the dam that may be damaged by the earthquake and realize rapid early warning for the dam.

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.

Combined with the operation management of reservoir dams, this paper first analyses the main contents of current research on engineering ethics in the field of hydraulic engineering. And then, based on social and natural dimensions, from the aspects of reservoir resettlement, reservoir degradation and decommision, public education, reservoir big data, reservoir management scope, reservoir aquaculture, biodiversity of reservoir area, etc., this paper discusses how engineers should correctly handle the interpersonal relationship as well as the relationship between mankind and nature in accordance with the code of engineering ethics.

The major dam shell of Xiaolangdi water conservancy project is filled with rockfill materials containing siltstone, clay rock and other soft rocks. After years of operation, the soft rocks on dam surface have weathered into fragments, and part of soft rocks have been eroded into rockfill voids, which will have a certain impact on the physical and mechanical properties of rockfill materials in the dam shell, such as the permeability coefficient and shear strength, and may also affect the stability of upstream and downstream dam slopes. At the same time, Xiaolangdi dam has large dam height, complex and deep overburden, many kinds of dam materials and complex operating conditions, so it is necessary to study the properties of rockfill materials in dam shell. Through in-situ excavation and sampling, relevant tests of the grading, compactness and permeability of rockfill materials and original rock character and strength are carried out to conduct the experimental study on properties of rockfill materials in the major dam shell. The results show that the main character parameters of rockfill materials in the major dam shell slightly changed, and the weathering degree and compressive strength of rockfill materials have limited influence.

To eliminate the malfunction of the air-release valve in the gate chamber not being able to close or close early when filling the tail water unit section of Changlongshan pumped storage power station, this article briefly analyzes the structure and weight of the floating bucket, as well as calculates the release area and the average release speed of key parts in the valve. By doing so, a transformation method is proposed under existing conditions, which is to increase the diameter of the floating bucket and release hole, and cancel the floating bucket counterweight. After multiple on-site tests, the optimized parameters of the air-release valve have been obtained. Since then, the water filling and air release process of the tailrace gate chamber have become safe and reliable.

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.

Regulations for operational safety management of hydropower dams are the basis for practice. This paper systematically sorts through the existing regulations for operational safety management of hydropower dams,as well as clarifies the functions of the regulations and the division of responsibilities in dam operation and safety management.Then it is pointed out that tight supervision is formed in China, namely the power enterprises take the main responsibility,the National Energy Administration and its agencies perform supervision duties and Large Dam Safety Supervision Center supplies technical super- vision services for dam operational safety.

This paper mainly discusses the similarities and differences about verification and test of static performance parameters such as non-linearity, hysteresis and repeatability of the sensor specified by SL 530—2012 Specifications for verification and test of dam safety monitoring instruments and DL/T 5178—2016 Technical specification for concrete dam safety monitoring. Moreover, the test results of a certain sensor according to those two specifications are presented.

At present, the cloud service platform for safety monitoring of small and medium-sized reservoirs in Xinjiang has been built, and the monitoring data from various regions have been collected to the cloud platform, which has gradually resulted in a large amount of safety monitoring data and has the basic characteristics of big data. With the rapid development of the Internet of Things, artificial intelligence, machine learning algorithms and other technologies, smart reservoirs have gradually become the development goal under the current situation. This paper mainly introduces how the data analysis model based on big data theory is applied to the safety monitoring platform of small and medium-sized reservoirs in Xinjiang, and the results show that the data analysis model based on big data theory has a good application result, which verifies the usability of big data theory in safety monitoring and the reliability of big data analysis model, as well as provides reference for monitoring data analysis of small and medium-sized reservoirs.

Sensors are needed on site to monitor the safety of water conservancy and hydropower projects.As well,cables are laid to monitoring stations to collect data.Specific installation structures are re- quired for monitoring sensors inside the building,and the centralized cables may exert certain impact on the project.This paper introduces the methods for cable connection,laying and protection,explores the layout and management of piezometer tubes for foundation of concrete dams,studies the installation structure of monitoring sensors for shield tunnels,proposes optimization measures,and proposes the use of horizontal and vertical waterproof cables for key parts of pumped storage power stations with ultra- high water pressure which can substantially reduce the potential risks caused by safety monitoring devices to hydraulic structures.The relevant experience has been successfully verified in practice and can be used as a reference for similar projects.

Among large and medium-sized hydropower stations in China, some of the older hydropower units that have been in operation for a long time have experienced a decline in performance and an increase in failure rates. It is of significance to take necessary technical measures to increase the capacity of the old units. Therefore, investigations and studies on the issue of hydropower unit capacity upgrading and renovation are carried out. Based on the survey, the existing problems and difficulties in the current implementation of hydropower unit capacity upgrading and renovation are analyzed and summarized, and suggestions are given for reference.

From the perspective of geological conditions, dam foundation uplift pressure, dam body temperature field and operation conditions, comprehensive analysis of the causes of abnormal horizontal displacement of an arch dam is carried out. It is concluded that the abnormal radial horizontal displacement is mainly caused by the unfavorable working conditions, including the water level surge in low temperature season as well as water level rise during sudden drop of temperature. Furthermore, the measured radial displacement does not exceed the designed calculation results, which may provide optimization recommendations for daily operations.

Due to the relatively concentrated timing of water distribution periods, in order to meet the needs of water allocation within the year and improve the water supply guarantee rate, the Xinjiwa reservoir is constructed in Zouping city, as supporting works for the first phase of the East Route Project of South-to-North Water Diversion. This project can realize the water supply goal of South-to-North Water Diversion Project and provide support for the regional national economic development. Focusing on the construction of dams for the reservoir, the design schemes are compared and selected from two aspects: reservoir storage depth and dam foundation seepage interception scheme. The selected design scheme can meet the requirements of the reservoir, and can provide reference for reservoir construction in water supply areas along South-to-North Water Diversion Project.

To facilitate the application of measured stress to evaluate dam concrete stress in practice, by analyzing the differences between the measured stress and the designed stress and their causes, and combining with calculation cases, a set of evaluation method and index is proposed, which is of reference significance for the application of the measured stress of dam concrete and the stress evaluation of hydropower dams during operation.

Detailed analysis of the geological conditions,scouring model,measured scouring data,and scouring pit depth of Penglatan hydropower station in Meijiang,Guangdong province is carried out.By analyzing the measured data of scouring pits and calculation of the scouring pits depth,it is pointed out that there is a potential risk of further scouring of the downstream riverbed.The development pattern of scouring pits is consistent with design expectations and hydraulic model test results.Currently,the impact of the scouring pit downstream on the gate foundation is still slight,but it is close to the safety threshold for slope control.To prevent further scouring,it is recommended that treatment of the scouring pits at the sluice gate and the guide wall of powerhouse gate should be carried out first.Moreover,on- site monitoring of the dam foundation and downstream riverbed should be strengthened.

The underground powerhouse of pumped storage power station is deeply buried, and is affected by many factors such as drainage gallery, water filling of tunnel, complex geological conditions and natural groundwater, so the complex seepage field is often formed. Based on the FEFLOW software, a three-dimensional steady state model of seepage including water transmission tunnel, underground powerhouse, drainage gallery, surrounding rock and fault is established. According to the simulation results, the initial seepage control and drainage scheme is optimized, eliminating unnecessary drainage galleries in the middle horizontal section and lifting drainage galleries in the lower horizontal section to discharge seepage water in the form of natural flow. The total seepage flow of drainage galleries and cavern group in the powerhouse area is 8 048.16 m ³ /d, which provides a greater flexibility for the selection of drainage pumps for underground powerhouse.

Dabi gully is located on the left bank, about 400 m upstream the dam site of KL hydropower station. The gully is straight, the main gully is 26.37 km long, the relative height difference of the gully is 2 487 m, and it is a moderately developed debris flow gully with micro-viscous debris flow. Due to construction needs, the dam concrete batching plant of KL hydropower station is arranged in Dabi gully. To guarantee the safety of concrete production and personnel, it is necessary to implement control measures for gully water and debris flow. Based on the topography and geological conditions of Dabi gully and the characteristics of debris flow, control measures such as grid-type dam, discharge tunnel, water intake tower and retaining dam, as well as monitoring instruments such as mud meter level and CCTV are adopted in the design for debris flow control. The design for debris flow control of Dabi gully can provide reference for similar projects in western China.

Based on the principle and characteristics of anchor cable dynamometer, the construction technology of prestressed anchor cable on the pier and the stress condition of prestressed pier, this paper puts forward the data recording requirements in the construction of prestressed anchor cable, discusses the key points in analysis of monitoring data from anchor cable dynamometer, and presents reasonable suggestions aiming to improve the stress monitoring design of prestressed anchor cable.