Key techniques for evaluation of safety monitoring sensors in water conservancy and hydropower engineering

For the evaluation of construction quality and the verification of the design of water conservancy and hydropower engineering projects, and especially for the control of dam safety operation behavior, safety monitoring sensors are employed in a majority of engineering projects. These sensors are used to monitor the project during the dam construction and operation periods, and play an important role in reservoir safety operation and producing benefits. With the changing of operating environments and run-time of projects, there are some factors affecting the operation and management of projects, such as a certain amount of damaged sensors and instability of the measured data. Therefore, it is urgent to evaluate existing safety monitoring sensors in water conservancy and hydropower engineering projects. However, there are neither standards nor evaluation guidelines at present. Based on engineering practice, this study examined some key techniques for the evaluation of safety monitoring sensors, including the evaluation process of the safety monitoring system, on-site detection methods of two typical pieces of equipment, the differential resistor sensor and vibrating wire sensor, the on-site detection methods of communication cable faults, and a validity test of the sensor measured data. These key techniques were applied in the Xiaolangdi Water Control Project and Xiaoxi Hydropower Project. The results show that the measured data of a majority of sensors are reliable and reasonable, and can reasonably reflect the structural change behavior in the project operating process, indicating that the availabilities of the safety monitoring sensors of the two projects are high

Analysis on the Problems of Solutions of Water Conservancy & Hydropower Engineering Cost Management

With the continuous development of society and economy in China, the number of water conserv ancy & hydropower engineering in China increases unceasingly and China s water conserv ancy industry also enters into the stage of rapid development. The construction of water conserv ancy & hydropower engineering promotes social and economic development, so in order to safeguard the benefits of the engineering, cost management shall be done well, which is also an important channel for companies engaging in water conservancy & hydropower engineering to obtain economic benefits. Based on this the paper firstly investigates the problems in water conserv ancy & hydropower engineering cost management and then brings up relevant solutions.

The Application of 3D Visualization Technology in the Construction of Water Conservancy and Hydropower

This paper put forward the structure and construction process of three-dimensional visualization of hydroelectric construction system model based on GIS and 3D visualization platform. The paper first describes the 3D visualization based on GIS, then discusses the method of constructing 3D visual digital model, and then introduces the terrain digital technology, feature modeling technology. Finally, the technical route shows that this method has good practicability.

Joint optimization scheduling for water conservancy projects incomplex river networks

In this study, we simulated water flow in a water conservancy project consisting of various hydraulic structures, such as sluices, pumping stations, hydropower stations, ship locks, and culverts, and developed a multi-period and multi-variable joint optimization scheduling model for flood control, drainage, and irrigation. In this model, the number of sluice holes, pump units, and hydropower station units to be opened were used as decision variables, and different optimization objectives and constraints were considered. This model was solved with improved genetic algorithms and verified using the Huaian Water Conservancy Project as an example. The results show that the use of the joint optimization scheduling led to a 10% increase in the power generation capacity and a 15% reduction in the total energy consumption. The change in the water level was reduced by 0.25 m upstream of the Yundong Sluice, and by 50% downstream of pumping stations No. 1, No. 2, and No. 4. It is clear that the joint optimization scheduling proposed in this study can effectively improve power generation capacity of the project, minimize operating costs and energy consumption, and enable more stable operation of various hydraulic structures. The results may provide references for the management of water conservancy projects in complex river networks.

Evaluation index system for positive operation of water conservancy projects

The conditions for the positive operation of water conservancy projects are described in this paper. A scientific and effective evaluation index system was established based on frequency analysis, theoretical analysis, and expert consultation. This evaluation index system can be divided into six first-level indices： the degree to which facilities are intact and functionality standards are reached, the status of operation and management funds, the rationality and degree of advancement of the management team structure, the adaptability and rationality of the water conservancy project management system, the degree of automatization and informationization of the management techniques, and the conduciveness of the exterior environment. The weights for evaluation indices were obtained through the analytic hierarchy process method with consideration of the difference between public welfare and profit-oriented water conservancy projects. This study provides a scientific method for evaluating the positive operation of water conservancy projects.

θ-improved limited tolerance relation model of incomplete information system for evaluation of water conservancy project management modernization

The modernization of water conservancy project management is a complicated engineering system involving a management system, a management method, management personnel, the exertion of social, economic, and ecological effects, and so on. However, indices for evaluating the modernization of water conservancy project management are usually unobtainable in practical applications. Conducting appropriate extension of the classical rough set theory and then applying it to an incomplete information system are the key to the application of the rough set theory Based on analysis of some extended rough set models in incomplete information systems, a rough set model based on the θ-improved limited tolerance relation is put forward. At the same time, upper approximation and lower approximation are defined under this improved relation. According to the evaluation index system and management practices, the threshold for θ is defined. An example study indicates the practicability and maneuverability of the model.

Analysis on Regulation Effect of Water Conservancy Project in Upper Reaches of Wujiang River,Guizhou on Runoff

Based on monthly runoff data of Hongjiadu,Guizhou from October 2013 to June 2015 and monthly runoff data of Yachi River,Guizhou from April 2014 to May 2015,using REOF and multiple linear regression analysis,regulation effect of water conservancy project in upper reaches of Wujiang River on monthly runoff of the river was analyzed. Seasonal temporal-spatial change of monthly runoff in Hongjiadu and Yachi River mainly contained two kinds of modalities. The first modality was that of Yachi River,which was main component of seasonal change of monthly runoff,and peak appeared in July. Space load of Yachi River modality was larger than Hongjiadu,and manual control ability of monthly runoff in Hongjiadu was larger than Yachi River. The second modality was that of Hongjiadu,and peak appeared in December. Space load of Hongjiadu modality was larger than Yachi River,and manual control ability of monthly runoff in Yachi River was larger than Hongjiadu. Seasonal changes of time components of two modalities had significant inverse phase. Regulation effect of Hongjiadu modality advanced Yachi River modality,and regulation effect of water conservancy project in Hongjiadu modality was larger than that of Yachi River modality,and seasonal distribution characteristics of regional rainfall was basically eliminated in Hongjiadu modality. Some seasonal distribution characteristics of regional rainfall were maintained in Yachi River modality. Monthly runoff modality of Yachi River had water storage regulation effect on a smaller part of regional monthly rainfall modality. Monthly runoff modality of Hongjiadu mainly had water storage regulation effect on south-north type of component of regional monthly rainfall,while most components of regional monthly rainfall modality did not have significant impact on monthly runoff modality of Hongjiadu.

A Study on Cost Control of Agricultural Water Conservancy Projects Based on Activity-based Costing

Based on the theory of activity-based costing and the idea of value chain,activity optimization and cost control are carried out on the whole construction process of agricultural water conservancy projects. Through the use of literature review,case analysis and statistical analysis and other methods,with agricultural water conservancy projects as the research object,and comparing activity-based costing with the traditional model of cost accounting,the writer carries out the corresponding value chain analysis,and comes to the following conclusion: the statistical calculation and analysis of the entire construction process based on activity-based costing can accurately and effectively control the costs of water conservancy projects. Through the use of activity-based costing,the cost data of agricultural water conservancy projects is more detailed and accurate,and cost management personnel can also find non-value-added activities,optimize the enterprise's value chain and achieve cost control objectives through the analysis of the activity chain and value chain of agricultural water conservancy projects.

Research on performance evaluation of small water conservancy facilities construction project in Hebei Province

This paper takes Hebei province of small water conservancy facilities construction project as the research object, the performance evaluation purposes of construction of farmland water conservancy facilities project, the data sources when carry out performance evaluation, performance evaluation procedures and limitations of farmland water conservancy facilities construction project performance evaluation were discussed.

River Treatment and Measures in Water Conservancy Projects of Small Farmland

China is country of massive agriculture.Although it has gradually changed from traditionalagriculture to modern agriculture in recent years, thereare still many problems in the transition. Rivers playan important role in water conservancy projects offarmland. Therefore, full attention should be paid toriver management of farmland. This thesis analyzes itand proposes countermeasures for governance.

Discussion on Anti-seepage Wall and Anti-seepage Technology of Water Conservancy Project

The water infiltration problem of water conservancy projects is one of the more common problems in the construction of water conservancy projects,which seriously affects the overall construction quality and safety of water conservancy projects.This article studies the causes of water infiltration in water conservancy projects and introduces related antiseepage technologies,hoping to be a reference for the implementation of anti-seepage projects.Through research,it is found that the factors that cause water infiltration in water conservancy projects include water conservancy project structural changes,environmental factors and construction factors.Relevant personnel can use concrete anti-seepage wall construction technology and high-pressure jet grouting technology to do the relevant anti-seepage work of water conservancy projects.

Research on the Present Situation and Improvement Strategy of Water Conservancy Project Construction Quality Management based on the Quality Efficiency Equilibrium Theory

In this paper, we conduct research on the present situation and improvement strategy of the water conservancy project construction quality management based on quality efficiency equilibrium theory. Water conservancy engineering construction enterprises should refer to oneself circumstance, and the characteristics of the water conservancy project, determine the quality objectives of specific quality assurance plan and the related measures, clear implementation content, methods and effects. Strictly control the factors influencing the water conservancy engineering quality of many aspects, in the process of the water conservancy project construction, to establish a meet the requirements of the technical process and quality standards, operation procedures. Establish the strict appraisal system, continuous improvement and improve the level of construction technique and technology. Establish strict quality assurance system and quality responsibility system, each division, subdivisional work will comprehensively implement in place management to ensure the engineering quality.

Discussion on Anti-Seepage Technologies in the Construction of Small-Scale Rural Water Conservancy Projects

In order to ensure the sustainable growth of rural economy,it is necessary to carry out further research on small-scale water conservancy projects and solve the seepage issue in rural areas.Based on the application significance of small-scale rural water conservancy projects and the analysis of anti-seepage technologies,along with specific examples,this paper specifically discusses the application of high-pressure jet technology,so as to provide reference for the development of engineering construction.

Analysis of unlined pressure shafts and tunnels of selected Norwegian hydropower projects

Norwegian hydropower industry has more than 100 years of experiences in constructing more than4000 km-long unlined pressure shafts and tunnels with maximum static head of 1047 m（equivalent to almost 10.5 MPa） reached at unlined pressure tunnel of Nye Tyin project. Experiences gained from construction and operation of these unlined pressure shafts and tunnels were the foundation to develop design criteria and principles applied in Norway and some other countries. In addition to the confinement criteria, Norwegian state-of-the-art design principle for unlined pressure shaft and tunnel is that the minor principal stress at the location of unlined pressure shaft or tunnel should be more than the water pressure in the shaft or tunnel. This condition of the minor principal stress is prerequisite for the hydraulic jacking/splitting not to occur through joints and fractures in rock mass. Another common problem in unlined pressure shafts and tunnels is water leakage through hydraulically splitted joints or pre-existing open joints. This article reviews some of the first attempts of the use of unlined pressure shaft and tunnel concepts in Norway, highlights major failure cases and two successful cases of significance, applies Norwegian criteria to the cases and reviews and evaluates triggering factors for failure.This article further evaluates detailed engineering geology of failure cases and also assesses common geological features that could have aggravated the failure. The minor principal stress is investigated and quantified along unlined shaft and tunnel alignment of six selected project cases by using threedimensional numerical model. Furthermore, conditions of failure through pre-existing open joints by hydraulic jacking and leakage are assessed by using two-dimensional fluid flow analysis. Finally, both favorable and unfavorable ground conditions required for the applicability of Norwegian confinement criteria in locating the unlined pressure shafts and tunnels for geotectonic environment different from that of Norway are highlighted.

Spatiotemporal evolution of water conservation function and its driving factors in the Huangshui River Basin, China

The Grain for Green project has had a substantial influence on water conservation in the Huangshui River Basin,China through afforestation and grassland restoration over the past two decades.However,a comprehensive understanding of the spatiotemporal evolution of water conservation function and its driving factors remains incomplete in this basin.In this study,we utilized the Integrated Valuation of Ecosystem Services and Tradeoffs(InVEST)model to examine the spatiotemporal evolution of water conservation function in the Huangshui River Basin from 2000 to 2020.Additionally,we employed the random forest model,Pearson correlation analysis,and geographical detector(Geodetector)techniques to investigate the primary factors and factor interactions affecting the spatial differentiation of water conservation function.The findings revealed several key points.First,the high-latitude northern region of the study area experienced a significant increase in water conservation over the 21-a period.Second,the Grain for Green project has played a substantial role in improving water conservation function.Third,precipitation,plant available water content(PAWC),grassland,gross domestic product(GDP),and forest land were primary factors influencing the water conservation function.Finally,the spatial differentiation of water conservation function was determined by the interactions among geographical conditions,climatic factors,vegetation biophysical factors,and socio-economic factors.The findings have significant implications for advancing ecological protection and restoration initiatives,enhancing regional water supply capabilities,and safeguarding ecosystem health and stability in the Huangshui River Basin.

Water Consumption by Hydropower, Does It Worth Allocation under Ethiopian Context

The Ethiopian water policy strictly follows water allocation as a principle in setting out water consumption problems and demand projection. Hydroelectric power plants supply the larger share (88%) of the electricity in Ethiopia. 86% of Ethiopia’s plan to 2020 energy supply is expected to be from hydropower. This paper defines water consumption in hydropower production as the quantity of water that leaves the analyzed projects (reservoir regulated hydropower projects) through evaporation. Water consumed by hydropower development has never been studied at a country scale. Thus, in attempting to understand water consumption by the hydropower development, this study will be the first to acknowledge the water consumption by all storage regulated hydropower plants developed in Ethiopia. While studying and designing reservoir regulated hydropower production, the overall effect of water consumption by the projects is assumed to be minimal;thus ignoring water allocation to hydropower projects is a common procedure in Ethiopia. In this study, for multipurpose projects, to identify the water consumption by hydropower against the other purpose (irrigation) consumption, water consumption factors based on economic benefits were used. The study has shown that the 14 existing and under construction reservoir regulated hydropower projects will consume 1.881 billion m3 of water annually. This will make hydropower the second most water consuming water resource development next to Irrigation in the country. Together with the 22 upcoming projects the water consumption will be 3.756 billion m3/year. The results also show that hydropower consumption in the country will take an average of 2.41% of the total water stored in a reservoir. This value is in the range of nearly zero for power projects that use natural lakes as their reservoir (Tana Beles, Tis Abay I & II) and GERD to 10.64%. The total reservoir volume that will be created in the country after completion of the 22 planned projects is larger than 233 BCM, which is greater than the surface water volume the country possesses. This indicates that the future water consumption by hydropower plants shall be revised in accordance with changes made in the final design of each planned projects. Nonetheless, this research provides scientific support for the argument that the production of hydroelectricity by reservoir regulated hydropower schemes, in countries like Ethiopia, is a water consumer. Thus, water allocation shall not ignore its demand.

Analysis of Winter Concrete Construction in Water Conservation Project

The construction of water conservancy projects should commence during optimal atmospheric conditions and non-flood period to ensure completion before the flood season begin in summer.In most areas of Northern China,the temperature during winter remain at lower level,in which environmental factors play the most important role in the construction of water conservancy projects.In particular,low temperature directly affects the strength of concrete and delays its solidification,this highly affects the quality and progress of concrete construction.In order to overcome this barrier,better planning,for reasonable and effective construction techniques and targeted control measures should be adopted to reduce the adverse effects of low temperature to assure a strong and safe architecture.

Influences of Water Conservancy and Hydropower Projects on Runoff in Qingjiang River Upstream Basin

Hydrological data on the Upper Qingjiang River from 1960 to 2012 document trends of runoff caused by hydropower engineering projects and long-term changes in rainfall. Annual runoff correlates strongly with annual precipitation, but is significantly reduced after reservoir construction compared to earlier values. Comparisons of intense, pre- and post-construction rainfall events suggest that the Chebahe and Dalongtan reservoir projects respectively clips the magnitude of the flood peaks and delays runoff delivery.

Study on Safety and Stability Evaluation of Waste Disposal Field of a Hydropower Station Based on <i>In Situ</i>Monitoring

Reasonable site selection, blocking to meet design standards, interception and drainage and other protective measures are the basic conditions for not causing disaster in slag disposal site. A hydropower station is located in mountainous area, the amount of slag abandoned is large, the grade of slag disposal field is high, and the site selection is difficult. On the basis of in Situ deformation monitoring, the slope stability of slag disposal site is calculated by Swedish arc method through the analysis of the scale, grade, site selection, surrounding environment, cut and discharge, blocking and protection design standards of slag disposal site. Under normal and abnormal operating conditions, the slope stability of slag disposal site meets the requirements of the code, and the results of in Situ deformation monitoring verify the calculation results of slope stability of slag disposal site by Swedish circular arc method.

软土地基上水利枢纽基础处理施工技术

对于水利枢纽工程而言,基础处理的科学性、合理性直接关系到工程的安全运行和经济效益。软土地基因其低承载力、高压缩性和流变特性,为水利枢纽工程的设计与施工带来诸多挑战,这些地质条件要求采用特定的工程技术以确保结构的稳定性和功能的可靠性。从搅拌桩的布置与施工、混凝土的浇筑与固化过程以及施工后的质量控制与验收等方面阐述了软土地基上水利枢纽基础处理的施工技术,最后对地基加固成效进行了评估,确保加固措施达到预期效果。