Volume 28, Number 10, October 2011
£Û Source£ºCRSRI   Author£º £İ

Enhancing Scientific Researches for Public Benefit to Support Water ª¤ Conservancy of the Yangtze River
GUO Xi-ling ª¤
(Yangtze River Scientific Research Institute, Wuhan 430010, China)

Abstract: The paper makes a detailed review on the development of public beneficial specialties of the Changjiang/Yangtze River Scientific Research Institute in the last decade. Innovative research achievements are presented in terms of flood control, drought relief and disaster mitigation, river regulation, water resources management, water and soil conservation, water ecology and environmental protection, river basin planning, and integrated water administration. In line with the new tasks of river regulation in the forthcoming years, considerations for the prospect of scientific researches for public benefit are put forward.
Key words: water conservancy of Yangtze River; scientific researches for public benefit; progress; prospect

 

Review and Prospect of CRSRI Mathematical Models of River Flow and Sediment Transport
DONG Yao-hua ª¤
(Key Laboratory of River Regulation and Flood Control of MWR, Yangtze River Scientific Research Institute, Wuhan 430010, China)

Abstract :Researches on mathematical models of river flow and sediment transport by Changjiang/Yangtze River Scientific Research Institute (CRSRI) can be traced back to the 1950s, with a series of computer software of ¡° Heliu ¡± (or ¡° River ¡± ) been developed over the last 6 decades of development and application. This paper makes a review on key mathematical models at CRSRI, which comprises the reservoir sedimentation model, river 1-D, 2-D and 3-D models, and other mathematical models and application practices, inclusive of estimating models, special models and imported models. Core technologies of numerical simulation of river flow and sediment transport are also presented. To establish a system for the models, improve the existing models, expand the modeling disciplines and applications, and make breakthroughs in modeling techniques are major tasks for the model development. The paper can be regarded as a guideline for the development of the models in CRSRI.
Key words: mathematical model of river flow and sediment transport; computer software of ¡°Heliu ¡±; hydraulics and river dynamics

 

Theoretical Analysis on Sediment Relative Hidden Degree and Its Application
YANG Wen-jun, MENG Zhen ª¤
(Key Laboratory of River Regulation and Flood Control of MWR, Yangtze River Scientific Research Institute, Wuhan430010, China)

Abstract :Relative hidden degree is of far-reaching importance to the research of incipient motion and transportation of sediment particles. This paper presents an overview on some of the research achievements by the author in the theory and application of sediment relative hidden degree, including the latest researches covering the different dimensionality of relative hidden degree, the regularity of its distribution, incipient velocity of sediment on bed slope and bank slope, demonstration on incipient characteristic of wide grading non-uniform sediment, analysis on Shields fillet curve, and experiment on underwater internal friction angle. Finally, prospect of its experiment research was looked forward.
Key words: relative hidden degree; incipient motion of sediment; bed slop; bank slop; Shields fillet curve; submarine internal friction angle

 

Study on the Method of Calculating Transport Rate of Discontinuous ª¤ Broadly Graded Bedload
XU Hai-tao, LU Jin-you, LIU Xiao-bin
(Yangtze River Scientific Research Institute, Wuhan 430010, China)

Abstract: The calculation method for bedload transport rate is studied by flume experiment, through which the effect of different flow intensities and bed material compositions on the transport rate of continuous and discontinuous broadly-graded bedload is investigated. A formula of relative flow intensity in consideration of non-uniform sediment is set up and regression analysis is carried out by using the experiment data. The relationship between relative flow intensity and bedload transport rate is further analyzed. This formula is proved to be rational as it reflects the effect of non-uniform discontinuous broadly-graded bed material on sediment transportation.
Key words :discontinuous broadly-graded; bed material; flume experiment; bedload transport rate

 

Joint Regulation of Large Reservoir Groups on Yangtze River
CHEN Jinª¤
(Yangtze River Scientific Research Institute, Wuhan430010, China)

Abstract:As the Three Gorges Project being finished and other large hydropower stations under construction in upstream Yangtze River, there is a growing urgent demand for the non-beneficial joint regulation of the reservoir groups for flood control, drought relief, and ecology. Based on the regional distribution and regulation capacity of constructed large reservoirs in Yangtze River basin, the demands of flood control, water power, water resource and eco-regulation posed by economic and social development are presented. Furthermore, the regulation capacity, technical condition, restricting factors, and the launching condition of non-beneficial regulation are analyzed. It is concluded that to coordinate the joint regulation of reservoir group and single reservoir operation, it is imperative to study and determine the launching condition and evaluation system of joint regulation, and to establish management mechanism of benefit negotiation and compensation.
Key words: Yangtze River; large reservoir groups; joint regulation; utilization of water recourses; environmental flow

 

Review on Biological Floating Island and Its Application in Water Ecological Restoration
HUANG Wei, ZHANG Jin, SANG Lian-hai ª¤
(Yangtze River Scientific Research Institute, Wuhan430010, China)

Abstract :Biological Floating Island (BFI) technology is widely used in water ecological restoration as it effectively improves the water environment on the one hand and builds good visual environment and has economic benefit on the other. The origin and development of BFI are introduced, and biological islands are classified. Researches on BFI all over the globe are also reviewed. Key technologies of BFI and their applications in water ecological restoration are presented based on years of experiences of BFI research and promotion in an illustration of the superiority of BFI technology applied in water ecological restoration. Last but not least, the main development direction is explored.
Key words: biological floating island; ecological restoration; planting on water; ecological floating bed; application

 

Review and Prospect of Researches on Basin Water Environment and Water Ecology by CRSRI
LI Qing-yun, HUANG Zhuo, HUANG Wei, TAN De-bao £¬ FAN Bei-lin
(Yangtze River Scientific Research Institute, Wuhan 430010, China)

Abstract :Major research achievements with respect to basin water environment and ecology by Changjiang/Yangtze River Scientific Research Institute (CRSRI/YRSRI) in the last decade are presented. Innovative research findings in particular, are underscored in terms of healthy Changjiang River, ecological water demand and eco-regulation, effect of water conservancy and hydropower plants on eco-environment, calculation and assessment of pollution load capacity, water environment monitoring and policy for accidental water pollution emergency, and water environment simulation as well as the monitoring and control of non-point source pollution. Prospects of the researches on basin water environment and water ecology are looked forward.
Key words: water environment; eco-environmental protection; pollution load capacity; eco-environmental impact assessment

 

Regionalization and Rating Scale in Health Assessment of the Yangtze River
XU Ji-jun, CHEN Jin, JIN Xiao-juan ª¤
(Yangtze River Scientific Research Institute, Wuhan430010, China)

Abstract :The regionalization and rating scale of the health assessment for the Yangtze River are expounded from the criteria of point, line, and area. The study is made according to the characteristics of the physical geography and river system in the Yangtze River basin based on conventions and existing norms. In light of the assessment by first grade indicators and multidisciplinary indicators, the conversion of index values among different criteria and scales and the calculation method are also proposed to provide technical reference for the health assessment.
Key words: river health; assessment scale; Yangtze River basin

 

Key Issues of Water Resources Allocation in Yangtze River Basin
CHANG Fu-xuan
(Yangtze River Scientific Research Institute, Wuhan 430010, China)

Abstract : Water resources in Yangtze River basin are abundant in total amount, yet are unevenly distributed in time and space with seasonal water shortage in some local areas. The water resources in Yangtze River basin, both in volume and quality, should be allocated in line with the demands of different seasons and be integrated with the balance among society, economy and eco-environment in the basin. The water resources allocation in important regions and dry seasons in association with stringent water resources management should be focused to achieve an optimized and rational allocation.
Key words: utilization and development of water resources; water resources allocation; Yangtze River basin; key issues

 

Characteristics and Prospects of Soil and Water Conservation in China
ZHANG Ping-cang, LIU Hong-hu ª¤
(Yangtze River Scientific Research Institute, Wuhan 430010, China)

Abstract: It is one of the basic state policies for China to protect water and soil resources as it is abundant in mountains yet with severe soil erosion problems. The basic theory, organizations and agencies, laws and regulations, and technologies with respect to soil and water conservation in the past few decades are summarized and compared with those of the other countries. It is concluded that soil and water conservation in China has developed a comprehensive system comprising educational and scientific institutions and organizations, mature techniques, and secured laws and policies. Meanwhile, problems of soil and water conservation in China are presented, and corresponding countermeasures are proposed.
Key words: soil erosion; soil and water conservation measures; model; laws and regulations

 

Spatial Distribution of Soil Erodibility Factor ( K ) in Central China
CEN Yi, DING Wen-feng, ZHANG Ping-cang ª¤
(Yangtze River Scientific Research Institute, Wuhan430010, China)

Abstract: Based on data of the second national soil survey, the soil erodibility factor ( K ) of central China was calculated by EPIC (Erosion ª² Productivity Impact Calculator) model, and the spatial distribution of soil erosion factor of different soil types was worked out. It was revealed that the K value of soils in central China mainly ranged from 0.09 to 0.39 , with high values in east and west Henan, and low values in south Hunan and the middle and east border of Hubei and Henan Province. There are 25 soil types in central China, among which cinnamon soil has the largest K value of 0.34 , followed by red clay of 0.31 and skeletal soil of 0.19 . The red soil, paddy soil, fluvoaquic soil, yellow soil, and yellow-brown soil, which are main soil types in central China, in total account for 72.63% of the whole area with K values respectively of 0.250 , 0.253 , 0.287 , 0.225 and 0.244. The above figures generally reflect the soil erodibility of central China region.
Key words: soil erosion; soil erodibility; K value figure; EPIC

 

Preliminary Study on Environmental Factors Influencing Natural Gravity Irrigation in Ziquejie Terrace
XU Wen-sheng 1, YOU Wei 2, LI Ya-long 1, CHENG Dong-bing 1, LIU Xiao-lu 1, ZHANG Ping-cang 1
(1. Yangtze River Scientific Research Institute, Wuhan 430010, China; 2.Monitoring Center of Soil and Water Conservation, Ministry of Water Resources, Beijing 100053, China)

Abstract: Located at Shuiche Town, Xinhua County of Hunan Province, Ziquejie Terrace is a newly discovered heritage of ancient rice farming. The natural gravity irrigation process in Ziquejie Terrace is analyzed in terms of flow movement and circulation, based on which the influencing factors on the process are summarized and studied. The gravity irrigation consists of two coupled processes, the SIP (surface irrigation process) and the UIP (underground irrigation process), of which the former dominates in rainy seasons while the latter prevails in dry seasons. The gravity irrigation process is mostly influenced by vegetation, geological and geomorphic condition, human activity and climate, all of which are indispensible for the natural gravity irrigation. Water source of the SIP, which comes from rainfalls intercepted and stored by vegetation, and water source of the UIP, which is offered by the underground ¡° stealthy reservoir ¡± formed by the terrace ' s special geological condition, hand in hand reallocate the water resources in the terrace region to ensure the irrigation in dry seasons. And the supplies of input water sources for the irrigation are increased by perpendicular change of climate characteristics in the terrace region. Moreover, the local farmer ' s careful cultivation on the terraces contributes to the storing and saving of irrigation water resources. The UIP speed is limited by the special geological condition, while is accelerated by the middle mountain landform and the steep slope. They interact, and result in an equilibrium, which finally guarantees the underground irrigation time in dry seasons.
Key words: Ziquejie Terrace; gravity irrigation; influencing factors; stealthy reservoir; water resources allocation

 

GIS-Based Analysis of Settlement Survey Data
HAN Xian-quan1 , LIANG Jun1 ,CAO Jing-sheng2 , GAN Xiao-qing1 , ZOU Shuang-chao1
(1. Yangtze River Scientific Research Institute, Wuhan 430010, China;ª¤ 2.Irrigation Technology Promotion Center of Xiangyang Municipality, Xiangyang 441000, China)

Abstract :The spatial analysis and 3-D analysis modules in GIS software were employed to analyze the monitoring data of dam settlement during impoundment. In addition, 3-D simulation graphs of the dam settlement in different periods plotted by TIN model were compared with other monitoring indexes. It 's revealed that the settlement thematic maps and statistical charts and diagrams are more rapidly and conveniently generated, and contain more information with more accuracy than those by traditional methods. The intuitive and vivid 3-D simulation graphs of the settlement provide technical support for the whole project by informing decision ª² makers and engineers the latest settlement and deformation situation. In conclusion, it ' s rapid and accurate in reflecting the settlement monitoring results.
Key words: reservoir impoundment; settlement monitoring; GIS; TIN

 

Advances in Model Test and Prototype Observation of Spiral Case ª¤ Structure in Hydroelectric Power Plant
ZHANG Qi-ling 1, WU He-gao 2 , LI Duan-you 1
(1. Yangtze River Scientific Research Institute, Wuhan 430010, China; 2.State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072, China)

Abstract :The research advances of model test and prototype observation applied in the research of Spiral Case Structure in hydroelectric power plant are reviewed. It is indicated that the model test research of the structure with a pad membrane should be promoted, and it ' s promising to employ the dynamic structural test technology in studying the dynamic characteristics of the structure; whereas the monitoring data fails to play its due role owning to the privacy protection for most of the existing monitoring data of the structure, which are rarely seen to be compared with the calculation results. It¡¯s of great importance to monitor the deformation and dynamic response of the structure during its operation. It is anticipated that the model test and prototype observation will both remain throughout the development of researches on the structure.
Key words: spiral case; model test; prototype observation; research advance

 

Unascertained Filtering and Grey Model Applied in Dam Deformation Prediction
LI Bo 1, LIU Ming-jun 2 , ZHANG Zhi-jun 3
(1.Yangtze River Scientific Research Institute, Wuhan 430010, China; 2.South Branch of China Power Investment Group Company, Guangzhou 510130, China; 4.Construction Design Office, Changjiang River Survey Planning Design and Research Institute, Wuhan 430010, China)

Abstract :Unascertained filtering and grey model are applied to predict dam deformation as the prediction accuracy is inevitably influenced by the gross error of observation sequence on the one hand and the short observation sequence itself on the other. The gross error of dam deformation observation sequence is detected and corrected by unascertained filtering method, and subsequently the grey model is employed to predict the dam deformation. The integration of the two processes is proved by case study to be of high practical value with remarkably improved prediction accuracy.
Key words: unascertained filtering method; grey model; dam deformation; prediction

 

Optimization and Application of Energy Dissipation Works for Ski Jump Spillway at High Dams
HUANG Guo-bing, XIE Shi-ping, DUAN Wen-gang ª¤
(Yangtze River Scientific Research Institute, Wuhan 430010, China)

Abstract :The ski jump energy dissipator has been most widely used in the energy dissipation of high dam, yet optimizations should be made according to the unique characteristics of different projects. The outlet structures of three different dam types investigated by Yangtze River Scientific Research Institute are taken to illustrate the research achievements. Different arrangements of energy dissipator have been made for the three dam types. First, for the centripetal concentration of discharge flow at Geheyan gravity arch dam, a combination of the asymmetric shrink of flaring pier at the surface spillway, asymmetric contraction of the recurved narrow slit at the deep outlet, and plunge pool, is arranged. Second, for the erosion and siltation in the energy dissipation area of the asymmetric narrow valley at Shuibuya concrete face rockfill dam, narrow slit flip buckets are arranged in a cascade. Third, to solve the erosion problem of spillway plunge pool in the case of maximum power dissipation at Goupitan double curvature arch dam, differential flip bucket and flow-separating dentated sill for surface outlet combined with collision of different jet angle at the middle outlet are applied. Practices of flood discharging at the projects indicated that these new types of energy dissipator successfully solved the energy dissipation problem for the projects, and thus could be referential for alike ski-jump energy dissipation of high dams.
Key words: energy dissipation of ski jump type; flaring pier; narrow slit flip buckets; plunge pool

 

Six Decades of Researches on Soil Mechanics and Engineering in Yangtze River Scientific Research Institute
BAO Cheng-gang, GUO Xi-ling, CHENG Zhan-lin ª¤
(Yangtze River Scientific Research Institute, Wuhan 430010, China)

Abstract :Researches on soil mechanics and engineering by Changjiang/Yangtze River Scientific Research Institute (CRSRI) over the last 6 decades are briefly presented in an overview on the main projects and their contributions to Yangtze River regulation and China ' s geotechnical engineering by the Department of Soil Mechanics Engineering. Research fields and achievements by the Department are introduced, and their significance to the discipline are evaluated. The research features and styles are also described.
Key words : CRSRI; scientific researches on soil mechanics and engineering; high rock-soil cofferdam in deep water at Three Gorges Project; researches on Shuibuya Project; innovative achievements

 

Study on the Stability of Expansive Soil Slope
CHENG Zhan-lin, LI Qing-yun, GUO Xi-ling, GONG Bi-wei ª¤
(Yangtze River Scientific Research Institute, Wuhan 430010, China)

Abstract :This paper presents some recent advances in the stability analysis of expansive soil slopes by the Changjiang/Yangtze River Scientific Research Institute. Types and distributions of fractures were investigated through researches on the expansive soils in the middle route of the South-to-North Water Diversion Project. It was revealed that differences existed between the fractures of expansive soils of the upper and the lower portions of ¡° the depth of atmosphere influence ¡±. The initial fractures in the lower portion were found to be obviously directional. By dilatancy analysis for the expansive soils with the same initial water content and water absorption, high linear relationship was obtained between the swelling strain and the mean stress in the semi-logarithmic coordinate. The determination of strength and new test method of expansive soils were provided considering heterogeneous anisotropic and nonlinear properties of the strength of expansive soils. The failure mechanism of expansion soils slopes was analyzed, and the deformation modes were also given. The overall stability of expansive soil slopes not only depended on gravity, but was also controlled by the strength of fracture planes; while the destabilization of the shallow soil body was mainly subject to the expansive deformation under moistening. Stability analysis methods were employed for expansion soli slopes with two deformation modes, and the results indicated that the slope stability could be precisely reflected by stability analysis achievements using strength test values.
Key words: South-to-North Water Diversion Project; expansive soil; slope; stability; fractures; computed tomography; deformation mode; stability analysis method

 

The Application of New In-site Rock Mass Test Technique in Hydropower Engineering
ZHOU Huo-ming, ZHONG Zuo-wu, ZHANG Yi-hu, LI Wei-shu, XIONG Shi-hu, FAN Lei
(Yangtze River Scientific Research Institute, Wuhan 430010, China)

Abstract: In complex geological environments, high geo-stress and strong unloading in particular, the rock mass of large hydropower projects in west China presents new phenomena which cannot be explained by the existing theories. New in-site test techniques were developed and imported to study the complicated problems regarding rock mechanics and rock engineering of large hydropower projects in west China, covering the rock mass deformation and failure mechanism, the characteristics of rock mass relaxation, the rheological behavior and characteristics of time-dependent failure of rock. In-site rock mass test techniques, inclusive of the rheological test with flexible bearing plate, the real-triaxial unloading test under high confining pressure with complicated stress paths, the triaxial rheological test and time ª² dependent failure of hard rock mass, and acoustic emission location technique for the deformation and failure of rock mass are briefly introduced. Initial achievements of applying these new techniques in studying complicated rock mechanics problems of large hydropower projects in west China were also presented.
Key words: in-site rock mass test technique; rock mass real-triaxial test; rock mass rheological test; time-dependent failure of rock mass; acoustic emission location technique

 

Technologies Applied in Tests on Engineering Properties of Thick Overburden and Cofferdam Materials
RAO Xi-bao 1 , HU Sheng-gang 1 , CHENG Yong-hui 1 , ZHU Guo-sheng 1 , Ding Hong-shun 1, ZUO Yong-zhen 1, ZHOU Xiao-wen 2
(1. Yangtze River Scientific Research Institute, Wuhan 430010, China; 2.School of Civil Engineering and Transportation, South China University of Technology, Guangzhou 510640, China)

Abstract: River diversion and closure and technology of cofferdam safety control with thick overburden is studied in a research project supported by the National Key Technology R&D program. In special topic 3 of the project, field test, laboratory test, physical modeling and numerical calculation are employed to investigate the engineering properties of thick overburden and cofferdam materials in the purpose of tackling the scale effect in engineering property tests on coarse-grained materials and determining the underwater dumping-filling density for the cofferdam with thick overburden. Wudongde, Baihetan and Shuangjiangkou Hydroelectric Station cofferdam projects are taken as background and case study for the special topic. The main content, technical route and important achievements of the topic are briefly presented. Detailed research approaches and achievements will be reported later.
Key words: cofferdam; thick overburden; centrifuge model test; scale effect; mechanical behavior; seepage characteristics

 

Seepage Control System and Structure Safety of Rockfill Cofferdam on Thick Overburden
ZHANG Jia-fa, LI Shao-long, PAN Jia-jun, JIANG Zhi-quan, LIU Jun ª¤
(Yangtze River Scientific Research Institute, Wuhan 430010, China)

Abstract: The characteristics of construction, structure and material, operation of cofferdam on thick overburden were analyzed. The challenges in cofferdam design and research, and the overall aims of seepage control system were discussed. The main content, technical route and important conclusions of studies on the safety of seepage control system and structures of cofferdam on thick overburden were presented.
Key words: cofferdam; overburden; seepage control; impervious body; deformation; safety

 

Dewatering Test in Deep Foundation Pit of Canal and Its Application
ZHANG Wei, DING Pei-zhong, XIAO Li, SHENG Xiao-tao ª¤
(Key Laboratory of Geotechnical Mechanics and Engineering of MWR, ª¤ Yangtze River Scientific Research Institute, Wuhan 430010, China)

Abstract :The coefficients of permeability of the aquifers around the deep foundation pit were comprehensively analyzed through dewatering tests based on the test results in the preliminary design stage. The deep foundation pit of the pumping station, which is in the entrance region of the canal project of water diversion from the Changjiang River to the Hanjiang River, was taken as an example. By analyses of the dewatering test results through both the formulas recommended by the specification of pumping test and the numerical simulation, the permeability coefficients of different aquifers were obtained. These coefficients provided basic data for the planning of foundation pit dewatering in the later stage. The dewatering plan was improved remarkably by the designers according to the dewatering test results.
Key words: water diversion from the Changjiang River to the Hanjiang River; canal; deep foundation pit; dewatering test; numerical analysis

 

Research Progress on the Stability of Expansive Soil Slope in the Middle Route of South-to-North Water Diversion Project
GONG Bi-wei, CHENG Zhan-lin, GUO Xi-ling, LI Qing-yun ª¤
(Yangtze River Scientific Research Institute, Wuhan 430010, China)

Abstract :Researches conducted by Changjiang/Yangtze River Scientific Research Institute on expansive soil in the middle route of South-to-North Water Diversion Project are reviewed, and the main achievements on the theory and test technology in this regard are summarized. In particular, research works related to the failure mechanism and treatment technology of canal in expansive soil regions supported by National Key Technology R&D Program are presented in details, and the latest achievements on expansive soil inclusive of the failure mechanism, rapid identification, shear strength tests, and treatment measures of expansive soil canal slope are introduced.
Key words: middle route of South-to-North Water Diversion Project; expansive soil; slope; stability; research progress

 

Application and Development of Geotechnical Centrifuge in Yangtze River Scientific Research Institute
CHENG Yong-hui, LI Qing-yun, RAO Xi-bao, LIU Ming ª¤
(Yangtze River Scientific Research Institute, Wuhan 430010, China)

Abstract: Geotechnical centrifuge is a large special equipment to study complex geotechnical engineering problems. As early as in the 1980s, the largest geotechnical centrifuge in china at that time with a total capacity of 300g-t and an effective capacity of 180g-t was built at Changjiang/Yangtze River Scientific Research Institute(CRSRI), which laid foundation for the development of centrifuge and centrifugal model test technology in china. The development history of geotechnical centrifuge at home and abroad is firstly summarized in this paper. The developing process of the first generation geotechnical centrifuge in CRSRI and its significance are introduced, and the main research work and achievements regarding the first generation centrifuge are reviewed. Moreover, the development and properties of the second generation geotechnical centrifuge of CRSRI are described in details, and the reliability of the test system is proved by centrifugal model tests completed recently.
Key words: geotechnical centrifuge; upgrade and reform; centrifugal model test

 

In-situ Monitoring of Canal Slope Treatment at the Expansive Rock Test Section in Xinxiang
LIU Ming, LIU Jun, TAN Feng-yi, ZOU Rong-hua
(Key Laboratory of Geomechanical Engineering of MWR, Yangtze River Scientific Research Institute, Wuhan 430010, China)

Abstract: Field tests have been made in the expansive rock test section(Luwangfen Section) to study the failure mechanism of and the treatment measures for expansive soil canal slope, which is considered as a key technology of the South-to-North Water Diversion Project. Based on the test results, two failure modes of unstable canal slope are put forward according to the stability monitoring and protection survey. The effects of the treatment measures are comprehensively evaluated, and treatment plans for the canal slope are proposed. Reinforced geogrid is recommended first and foremost in the treatment; while soilbag can be used at the outlet or twisted section where spot treatment is required; and composite geo ª² membrane, as it has no weights effect, can be used at the canal slope above the first berm with low groundwater level and little lateral recharge.
Key words: South-to-North Water Diversion Project; expansive rock; treatment measures; monitoring; stability; protection

 

Technology of Underwater Rock Plug Blasting and Its Application in ª¤ Water Intake Project of Tangzhai Power Plant
LIU Mei-shan, TONG Ke-qiang, YU Qiang, ZHAO Gen, ZHANG Zheng-yu ª¤
(Yangtze River Scientific Research Institute, Wuhan 430010, China)

Abstract :The technology of underwater rock plug blasting includes chamber blasting, drilling blasting and the combination of both. The advantages and shortcomings of these three approaches and the application conditions are analyzed as follows: chamber blasting releases great power and thus is suitable for thick rock plug with large cross section; whereas drilling blasting, with evenly distributed power, can be applied in the blasting of small and medium-sized rock plug; and the combination of the both can be applied more widely in different engineering circumstances. The structural characteristics of double rock plugs in parallel sections are analyzed, based on which a blasting plan combining the large diameter deep hole and shallow hole blasting is proposed. Techniques of the blasting are also summarized for reference for alike projects. The water intake project of Tangzhai Power Plant is taken as an illustration.
Key words : rock plug blasting; Tangzhai power plant; chamber blasting; drilling blasting

 

Triaxial Test on Single Specimen by MTS Rock Mechanical Test System
WANG Bin, ZHOU Ruo, ZHU Jie-bing, WU Ai-qing
(Yangtze River Scientific Research Institute, Wuhan 430010, China)

Abstract :The method of triaxial testing on single specimen proposed by ISRM (International Society for Rock Mechanics) needs to be further studied as the servo controlling performance, the deformation measurement techniques and the monitoring approach for rock failure have improved. MTS815 testing system is one of the most excellent instruments in rock mechanics testing for its outstanding loading system, controlling system and measurement system. Based on this system, conventional triaxial tests and multiple level loading triaxial test are carried out on single specimen of Jinping coarse crystalline marble. It is revealed that the strength parameters of internal friction angle and cohesion by single specimen method are both smaller than those by conventional triaxial compression test, and the gap between the two parameters gets smaller with the confining pressure increases. It is concluded that the triaxial tests on single marble specimen with multiple level loading are suitable, feasible and reliable for low and moderately hard brittle rock. The conclusions will be of great practical value for the determination of mechanical parameters under special conditions and for the promotion of this method.
Key words : MTS815; triaxial test on single specimen; conventional triaxial test; stress level; strength parameters

 

Study and Application of CW Epoxy Resin Chemical Grouting Materials
WANG Zai-qin, WEI Tao, LI Zhen, JIANG Shuo-zhong, XUE Xi-liang ª¤
(Yangtze River Scientific Research Institute, Wuhan 430010, China)

Abstract: The paper introduced a series of amphiphilic CW Epoxy Resin Chemical Grouting Materials which comprise reactivity surfactants, low viscosity epoxy resin as basic agent, and non-toxic, highly tough curing agent which can be solidified in water. The material is featured by low initial viscosity, long operational time, adjustable gel time, good permeability and high mechanical strength. The successful application of this material in concrete crack repair, the consolidation grouting in fault zone, and anti-seepage grouting at the foundation of corrosion zone manifested that the percolation and consolidation of crushed rock zone and silted intercalation could be resolved by CW Epoxy Resin Chemical Grouting. It provides a new approach of improving rock foundation treatment and concrete crack reparation. The key technology of this material is to increase the permeability and infiltration capacity of grouting while ensuring the high strength of its solidity. The permeability and infiltration of the grouting depends not only on viscosity but also on the affinity and surface tension. It is mainly hydrophobic yet also hydrophilic.
Key words: CW epoxy resin; chemical grouting materials; high strength; high permeability; surfactant

 

Deterioration of Concrete Properties During Freeze-Thaw Cycles
LI Jia-zheng, ZHOU Shi-hua, SHI Yan
(Yangtze River Scientific Research Institute, Wuhan 430010, China)

Abstract :The deterioration of concrete properties from freeze-thaw actions are studied and the sensibility of various test methods to different deteriorating characteristics is also explored. It is revealed that the flexural strength and splitting tensile strength of concrete deteriorates more rapidly than compressive strength does, which is positively linearly related to mass loss rate and relative dynamic modulus of elasticity. When relative dynamic modulus of elasticity and mass of concrete are reduced respectively by 40% and 5%, the compressive strength is decreased respectively to 19.3% and 25.5% of the initial value. The sensibility of dynamic mechanical velocity to concrete deterioration during freeze-thaw cycles is between that of concrete strength and ultrasonic velocity. The density of hydration products of cement is decreased due to freeze-thaw actions, giving rise to cracks on the bubble wall and increase of porosities with diameter from 25 nm to 75 nm.
Key words: concrete; freeze-thaw cycles; deterioration; test; microscopic structure

 

Study and Application of CW Series Concrete Surface Protection and Patching Materials
WEI Tao, LIAO Ling-min, HAN Wei, XIAO Cheng-jing, LI Zhen, WANG Zai-qin ª¤
(Yangtze River Scientific Research Institute, Wuhan 430010, China)

Abstract: The surface of hydraulic concrete must be protected and repaired to improve its durability. To this end, a new type of CW series concrete surface protection and patching materials, namely nano-silicon dioxide/polyurea composite materials were synthesized by researchers in Yangtze River Scientific Research Institute. The materials were produced through ultrasonic dispersion by adding organosilane coupling agent, reactive diluent and nano-silicon dioxide to the synthcticfat of polymerization of polyaspartic esters and isocyanates. Meanwhile, the effects of ultrasonic dispersion time, the amount of nano-silicon dioxide, and the type and amount of isocyanate on the properties of the composites were explored. It was found that the newly developed materials were environmentally friendly, highly durable and cohesive and could be easily operated under dry and wet conditions, which could effectively improve the properties against ultraviolet aging, abrasion, permeability, carbonization, frost, and chemical corrosion of concrete. In this sense, they can be widely used in danger-eliminating and reinforcing for old hazardous reservoirs, surface protection and crack repairing of new hydraulic constructions, as well as other anti-seepage and anti-aging projects in hydraulic engineering. Up until now, the materials have been applied in the danger-eliminating and reinforcing of Three Gorges Dam, Danjiangkou Dam, the Middle Route Project of the South-to-North Water Diversion Project, Yichang Tangduhe reservoir and Shangjiahe reservoir.
Key words : polyaspartic esters; polyurea; nano composites; hydraulic concrete; durability

 

Mechanical Behavior of Prestressed Double Composite Linings of Yellow-River-Crossing Tunnel
XIE Xiao-ling, SU Hai-dong
(Yangtze River Scientific Research Institute, Wuhan 430010, China)

Abstract :The mechanical behavior of double composite linings of the Yellow-River-Crossing tunnel is analyzed by using 3-D non-linear finite element method when contacts between assembled segments of outer linings, and contacts between the inner and outer linings are considered. The above numerical calculation is compared with the 1:1 simulation test of two models with and without cushions between the inner and outer linings. The test process, inclusive of the segments assembling, layered earth filling, pretensioning of inner linings, and the applying of water pressure, is fully simulated. In the model without cushions, despite the fully-opened gap between the inner and outer linings, pretension loads upon the inner linings are partly transferred to the outer linings through steel bars, which is proved to be critical for joint load bearing of the double linings; whereas in the model with cushions, stresses of the outer linings increase slightly under the pretension and water pressure loads, revealing that the inner linings are subjected independently to these loads. The numerical values are close to test values in terms of the distortion, the stresses, and the gap between the inner and outer linings.
Key words: South-to-North Water Diversion Project; Yellow-River-Crossing tunnel; double composite lining; 3-D finite element; contact nonlinearity

 

Study on Flow-Induced Vibrations of the Slide Plane Gate at the Bottom Outlet of Xiangjiaba Dam
ZHANG Lin-rang, JIANG Yu-zhou, ZENG Ping, WU Jie-fang
(Key Laboratory of Geotechnical Mechanics & Engineering of MWR, ª¤ Yangtze River Scientific Research Institute, Wuhan 430010, China)

Abstract :Hydraulic tensioning steel halter is planned to be equipped for the opening and closing of the slide plane gate at the bottom outlet of Xiangjiaba dam. It is the first to install this equipment in hydropower projects. The flow-induced vibration of the gate is highly concerned as the large-sized gate opens and closes at the speed of 5m /h with high water head. Hydroelastic 1:30 model and numerical model are employed to obtain the dynamic properties, the static and dynamic stresses of the gate structure, the fluctuating pressure on the gate and the vibration characteristics, all of which are verified by tests and calculations. The study finds no resonance during the closing and opening of the gate, which thus is dynamically safe with small vibration. In addition, it is suggested to set up aeration facilities at the entrance of the bottom outlet to release the negative pressure on the back of gate and add extra weight to the gate to enable it closing easily.
Key words : xiangjiaba dam; bottom outlet; slide plane gate; flow-induced vibration; hydroelastic model; finite element calculation

 

Application of Digital Basin in Modern Watershed Management
TAN De-bao
(Yangtze River Scientific Research Institute, Wuhan 430010, China)

Abstract :The basic concept and recent research progress of Digital Basin (DB) are introduced in the light of the strategic demand of water resource development in the new era. Key technologies inclusive of the basic framework and technical standards, the comprehensive observation system involving space, air, and ground data, the organization, processing and sharing of multi-source mass spatio-temporal data, and multi-disciplinary model integration and application are discussed in detail. The practices of applying digital basin to the operation and management of Three Gorges Project are analyzed. The applications are summarized and looked forward.
Key words : digital basin; spatial information technology; modern watershed management

 

Measurement and Analysis of Greenhouse Gas Fluxes from Shuibuya Reservoir in Qingjiang River Basin
ZHAO Deng-zhong 1,2 , TAN De-bao 1 , WANG Zhao-hui 1 , HAO Chao-ying 1
(1. Yangtze River Scientific Research Institute, Wuhan 430010, China;ª¤ 2.China Three Gorge Corporation, Yichang 443002, China)

Abstract :The Shuibuya Reservoir on Qingjiang River was selected to illustrate the source and sink of greenhouse gas from the cascade hydroelectric power stations. In-situ measurements were carried out in May and October, 2010 to obtain carbon dioxide and methane exchange fluxes from water-atmosphere interface of the reservoir, the vertical profile of greenhouse gas concentration above water-body and the aquatic environmental factors respectively. It is revealed that the highest carbon dioxide concentration measured in May, 2010 was below 0.5 meter in the vertical profile, and the water surface temperature has the largest effect on the concentration change and fluxes of carbon dioxide from the reservoir 's water-body. Overall, carbon dioxide and methane was emitting from the water-atmosphere interface of Shuibuya Reservoir's water-body in October, 2010, with the mean fluxes amounting 3 740.92 ¡À1 872.56 mg.m-2d -1 and 1.22¡À0.57mg.m-2d -1respectively, close to those from Taihu Lake and East Lake and other natural water bodies in China, much lower than those from the reservoirs in the tropic or temperate zones. The carbon dioxide fluxes increased from the upstream to the dam; while methane fluxes presented to be the opposite. This study provided in-situ measured data for understanding the sink and source of greenhouse gas emission from reservoirs and scientific support for the development of hydroelectric clean energy of the upstream Yangtze River.
Key words : the Shuibuya reservoir; greenhouse gas emission from reservoir; exchange fluxes; water-atmosphere interface

 

Effects of Image Misregistration on the Accuracy of Change Detection ª¤ for High Resolution Remotely Sensed Images
SHEN Shao-hong 1 , GUO Xin-min 2
(1.Yangtze River Scientific Research Institute, Wuhan 430010, China; 2.Management Office of Shibalibao Reservoir on Gulang River in Gansu Province, Wuwei 733109, China)

Abstract: The effects of image misregistration on the accuracy of change detection for high-resolution remotely sensed images were quantit, atively investigated on the basis of multi-temporal geometrical registration. The relationship of misregistration respectively with bands and land complexity were firstly analyzed and evaluated. The sensitivity of each band and the difference among each region with different land complexity were then analyzed when misregistration errors are the same. The experimental results using QuickBird true-color images of four regions indicated that the misregistration had different impact on each band, and had more evident impact on regions of high land complexity with more false information generated.
Key words: image misregistration; high resolution remotely sensed image; change detection; accuracy assessment

 

Land Radiance Fog Detection in the Daytime Based on Normalized Difference Fog Index
WEN Xiong-fei 1 , TAN De-bao 1 , CHEN Bei-qing 1 , LIANG Yi-tong 2 , XIAO Xiao 1ª¤
(1.Yangtze River Scientific Research Institute, Wuhan 430010, China; ª¤ 2.Wuhan Regional Climate Centre, Wuhan 430074, China)

Abstract :A parameter named Normalized Difference Fog Index (NDFI) is proposed to detect land radiation fog based on analyzing the spectral character of fog and cloud in visible, short infrared and middle-infrared wave band by employing the Streamer radiative transfer model and the MODIS data. Threshold is set according to the histogram. It is demonstrated by two cases over mainland China in winter that this NDFI parameter could be applied to perform land radiance fog detection with high accuracy.
Key words: land radiance fog detection; EOS/MODIS; Normalized Difference Fog Index(NDFI); Streamer

 

Application of MSF Process Model in Integrated Information System for Office Management
LIU Pei, ZHOU Li-feng ª¤
(Yangtze River Scientific Research Institute. Wuhan 430010, China)

Abstract :The establishment of an integrated information system for office management based on Microsoft Solutions Framework (MSF) model is presented in line with model-development theories of software engineering. The iterative process of system demand collection, design, R&D, testing and deployment is introduced, and the application result is verified in terms of the software development efficiency, user ' s involvement and satisfaction. It is manifested that MSF model fits well with user ' s demand. The software development efficiency is improved, and the complexity of system building is greatly eased.
Key words : MSF model; integrated information system for office management; demand analysis; software engineering; process iteration

 

Review on Technology Innovation of Hydroturbine Governor and Its Prospect in China
PAN Xi-he, WANG Li-juan ª¤
(Changjiang Control Equipment Research Institute, Yangtze River Scientific Research Institute, Wuhan 430010, China)

Abstract :The paper presents an overall introduction to the development of technologies and products of hydroturbine governor in China, and makes a review on the latest technology innovation with respect to the speed governor ' s system structure mode, the structure of microcomputer regulator, diversified electro-hydraulic conversion components, the system redundancy, the computer simulation test, and the friendly man-machine interface with abundant information as well as the hydraulic pressure levels. It is indicated that the main performance indexes of hydroturbine microcomputer governor have generally met the requirements of the state technology standard, with some at the international advanced level. Problems worth attention by the industry are also discussed, and the prospect is looked forward.
Key words : hydroturbine; microcomputer governor; Industrial Personal Computer; electro-hydraulic conversion; servo system; technology innovation

 

 

 

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