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THE ALGORITHMS AND APPLICATIONS FOR DETERMINING PERMEABILITY COEFFICIENTS BY PULSE SPECTRUM TECHNIQUE

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Journal of Hydrodynamics 2002年第2期14卷 112-115页

作者： Wang Ling-ling College of Water conservancy and {2. Engineering, hohai university, Nanjing 2.0098, china Coll. of Water conservancy Hohai Univ. Nanjing 210098 China

The determination of inhomogeneous permeability coefficient was studied as a parameter-control inverse problem for parabolic-type equation in this paper. By virtue of PST, the solution of the inverse problem is converted into an iteration procedure of solving a direct problem and solving a Fredholm integral equation of the first kind. Besides, Tikhonov normalization method is introduced to treat the uncertainty caused by the integral equation. Thus an algorithm for determining inhomogeneous permeability coefficient has been formulated and implemented. Numerical results show: (1) The algorithm presented in the paper is suitable to strongly inhomogeneous seepagel; (2. The additional information needed for solution is merely the seepage velocity on partical boundary, so that drill works can be reduced remarkably; (3) The algorithm is applicable to determining inhomogeneous transmission coefficients in groundwater engineering or other engineering.

关键词： inverse problem Pulse Spectrum Technique (PST) permeability coefficient parameter identification

Game model of safety monitoring for arch dam deformation

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Science china(Technological Sciences) 2008年第S2期51卷 76-81页

作者： SU HuaiZhi1,2.WU ZhongRu1,2.GU YanChang1,2.HU Jiang1 & WEN ZhiPing3 1 College of Water conservancy and {2. Engineering,hohai university,Nanjing 2.0098,china 2.National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety,Nanjing 2.0098,china 3 Department of Computer Engineering,Nanjing Institute of Technology,Nanjing 2.0013,china College of Water conservancy and {2. Engineering Hohai University Nanjing China National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety Nanjing China Department of Computer Engineering Nanjing Institute of Technology Nanjing China

Arch dam deformation is comprehensively affected by water pressure,temperature,dam's structural behavior and material properties as well as other *** them the water pressure and temperature are external factors(source factors) that cause dam deformation,and dam's structural behavior and material properties are the internal factors of deformation(resistance factors).The dam deformation is the result of the mutual game playing between source factors and resistance ***,resistance factors of structure and materials that reflect resistance character of arch dam structure are introduced into the traditional model,where structure factor is embodied by the flexibility coefficient of dam body and the maximum dam height,and material property is embodied by the elastic modulus of *** the basis of analyzing the correlation between dam deformation and resistance factors,the game model of safety monitoring for arch dam deformation is put forward.

关键词： arch dam deformation monitoring model flexibility coefficient game theory

Computational theory of cavitating flows for hydraulic turbomachinery with consideration of influence of water quality

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Science china(Technological Sciences) 2010年第12期53卷 3341-3348页

作者： WANG Lei1,2.& CHANG JinShi2.1 Huadian Electric Power Research Institute, Hangzhou 310030, china 2.College of Water {2. and Civil Engineering, china Agricultural university, Beijing 100083, china Huadian Electric Power Research Institute Hangzhou China College of Water conservancy and Civil Engineering China Agricultural University Beijing China

Previously it was assumed that the pressure within the cavity or on the cavity surface remained constant and the vapor pressure of clean water at 2.°C and 0 m altitude was utilized as the computational boundary for cavitating flows in hydraulic turbomachinery. Cavitation was confused with vaporization, and the effect of water quality on cavitation pressure characteristics was not taken into account. In recent years, lots of experiments of cavitation pressure characteristics of different water qualities including different sand concentrations of sand water and different altitudes of clean water have been performed by the authors, and the important influences of water quality on cavitation pressure characteristic have been validated. Thus the water quality should be involved in the cavitating flows computation. In the present paper, the effect of water quality on the cavitation pressure characteristic is analyzed and the computational method and theory of cavitating flows for hydraulic turbomachinery that considers the influence of water quality are proposed. The theory is suitable for both the potential flow method and the two-phase flow method for cavitating flows simulation. Finally, the validation results for cavitating flows in a hydraulic tur- bine indicate the significant influences of water quality on the cavitating flow performance.

关键词： cavitating flows cavitation pressure water quality hydraulic turbomachinery

Back analysis of mechanical parameters of roller compacted concrete dam

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Science china(Technological Sciences) 2010年第3期53卷 848-853页

作者： GU ChongShi 1,2.3,LI Bo 1,XU GuangLei 4 &YU Hong 1,2.3 1 State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering,hohai university,Nanjing 2.0098,china {2. of Water conservancy hydropower,hohai university,Nanjing 2.0098,china 3National Engineering Research Center of Water Resources Engineering Safety,Efficient Utilization and Nanjing 2.0098,china 4 Nanjing Hydraulic Research Institute,Nanjing 2.002.,china State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University Nanjing China College of Water conservancy {2. Hohai University Nanjing China National Engineering Research Center of Water Resources Engineering Safety Efficient Utilization and Nanjing Nanjing China Nanjing Hydraulic Research Institute Nanjing China

In view of the diversity and complexity of mechanical parameters of roller compacted concrete dam(RCCD),the uniform design method,partial least-squares regression(PLS)and least squares support vector machine(LSSVM)were applied to the back analysis of RCCD with the use of the complex nonlinear relationship between dam mechanical parameters and dam *** the process of back analysis,the initial samples of parameters were designed with uniform design ***,a transversely isotropic model of RCCD was established by *** *** this model,training samples of LSSVM model could be *** then,the complex nonlinear relationship between relative values of hydraulic components of dam displacements and mechanical parameters was ***,actual relative values of dam hydraulic components are isolated from the measured data of dam displacements by using *** inputting the isolated relative values into LSSVM model,the back analysis values of RCCD mechanical parameters can be *** example analysis showed that mechanical parameters obtained by the above-mentioned back analysis method are reasonable,and the back analysis method is feasible.

关键词： roller compacted concrete dam mechanical parameters back analysis

Risk analysis model for landslide mass of high slope in dam area

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Science china(Technological Sciences) 2008年第S2期51卷 25-31页

作者： GU ChongShi1,2.HE XianFeng3,4,WU ZhongRu1,2.& SU HuaiZhi1,2.1 College of Water conservancy and {2. Engineering,hohai university,Nanjing 2.0098,china 2.National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety,Nanjing 2.0098,china 3 Yellow River Institute of Hydraulic Research,Zhengzhou 450003,china 4 Embankment Security Defect Prevention and Control Engineering Research Center of MWR,Zhengzhou 450003,china College of Water conservancy and {2. Engineering Hohai University Nanjing China National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety Nanjing China Yellow River Institute of Hydraulic Research Zhengzhou China Embankment Security Defect Prevention and Control Engineering Research Center of MWR Zhengzhou China

In order to identify the threat of reservoir bank landslide to dam safety and reduce the risk of dam failure,impact factors of the landslide are *** concept of landslide risk degree is put forward to measure the threat of landslide to dam *** monotony of the landslide risk assessment function which changes with different affecting factors is analyzed *** on gene automatic programming,a data mining model of the landslide risk assessment function is constructed combined with impact factors of reservoir bank landslide on dam *** the assessment function of landslide risk has been excavated and established according to practical project information,which provides a valuable reference for analyzing the impact of landslide on dam risk.

关键词： landslide dam failure risk landslide risk

Deterioration Mechanisms of Sulfate Attack on Concrete under Alternate Action

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Journal of Wuhan university of Technology(Materials Science) 2010年第2期25卷 355-359页

作者：高润东 State Key Laboratory of Hydroscience and Engineering Tsinghua University

By micro- and macro-observations, the deterioration mechanisms of concrete under alternate action between repeated sub-high temperature/cooling by water and sodium sulfate solution attack （TW-SA） were studied; meanwhile, the single sodium sulfate solution attack （SA） was also done as comparison. Micro-observations included the analysis of attack products by thermal analysis method and the determination of sulfate-ion content from surface to interior by chemical titrating method （modified barium sulfate gravimetric method）. Macro-observations mainly included the mechanical behaviors such as compressive strength, splitting strength. The experimental results indicate, in both cases, the main attack product is ettringite, only in the first layer of case SA some gypsum is checked; in case SA, the sulfate ions mainly concentrate in the surface layer, so the attack is relatively mild; but in case TW-SA, the repeated sub-high temperature/cooling by water promotes the sulfate ions diffusing inwards, which leads to obvious strength degradation.

关键词： concrete sulfate repeated sub-high temperature/cooling by water attack product sulfate-ion content strength

Influence of fractality of fracture surfaces on stress and displacement fields at crack tips

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Science china(Technological Sciences) 2008年第S2期51卷 95-100页

作者： BAO TengFei,WU ZhongRu,GU ChongShi & GU YanLing College of Water conservancy and {2. Engineering,hohai university,Nanjing 2.0098,china College of Water conservancy and {2. Engineering Hohai University Nanjing China

In the classic theory of fracture mechanics,expressions for calculating the stresses and displacements in the vicinity of the crack tip are deduced on the basis of the assumption that a fracture surface is a smooth surface or that a crack is a smooth *** fact,the surface of a crack formed during the fracture is usually very *** the real asymptotic form of the stress and displacement fields at the crack tip is different from the classic *** the irregularity of a real fracture surface or a real crack profile,the crack is taken as a fractal one,and then the real asymptotic form at the crack tip is developed by applying Griffith's energy balance principle and fractal *** the developed asymptotic form,it is discovered that the fractality of the crack reduces the stress singularity at the crack tip.

关键词： fracture surface crack fractal stress and displacement fields

Efficiency of sediment transport by flood and its control in the Lower Yellow River

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Science china(Technological Sciences) 2004年第Z1期47卷 173-185页

作者： NI Jinren1, LIU Xiaoyong2. LI Tianhong1, ZHAO Ye’an3 & JIN Ling1 1. Department of Environmental Engineering, Peking university The Key Laboratory of Water and Sedi- ment Sciences, Ministry of Education, Beijing 100871, china 2. General Institute of Water Resources and {2. Planning and Design, Ministry of Water Re- sources, Beijing 100011, china 3. The Yellow River conservancy Commission, Zhengzhou 450003, china Department of Environmental Engineering Peking University Beijing China The Key Laboratory of Water and Sediment Sciences Ministry of Education Beijing China General Institute of Water Resources and hydropower Planning and Design Ministry of Water Resources Beijing China The Yellow River conservancy Commission Zhengzhou China

This paper presents the characteristics of sediment transport by flood in the Lower Yellow River with the reach from Huayuankou to Gaocun, which is regarded as a typical braided pattern. The Artificial Neural Network Model on Water Use for Sediment Transport (WUST) by flood was established based on the measured data from 1980 to 1998. Consequently, simulations of controlling process of sediment transport by flood were made in terms of the control theory under different scenarios. According to the situation of sediment transport by flood in the Lower Yellow River, Open-Loop control system and feedback control system were adopted in system design. In the Open-Loop control system, numerical simulations were made to reveal the relationship between average discharge of flood and the WUST with varying sediment concentrations. The results demonstrate that sediment concentration has significant influence on the controlling process of flood flow to WUST. It is practical and efficient to control WUST if sediment concentration is less than 2. kg/m3. In the feedback control system, controlling processes of sediment concentration and flood discharge for sediment transport were simulated respectively under given conditions, and it was found that sediment transport process could be controlled completely by sediment concentration and discharge at the inlet of the reach from Huayuankou to Gaocun. Using the same method, controlling processes of sediment transport by flood in other reaches in the Lower Yellow River were also simulated. For the case of sediment concentration being 2. kg/m3, the optimized controlling discharge ranges from 2.90 to 2.00 m3/s in the lower reach of Huayuankou. This study is also of significance to flood control and flushing sediment in the Lower Yellow River with proper operation modes of Xiaolangdi Reservoir.

关键词： the Lower Yellow River, flood, sediment transport, efficiency, simulation, control.

EFFECTS OF HYDRAULIC AND GEOMETRIC PARAMETERS ON DOWNSTREAM CAVITY LENGTH OF DISCHARGE TUNNEL SERVICE GATE

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Journal of Hydrodynamics 2009年第6期21卷 774-778页

作者： MOHAGHEGH A College of Water conservancy and {2. Engineering Hohai University

Aerators on discharge tunnel outlets may be regarded as an effective protection against cavitation erosion. The air entrainment of aerators is governed by a number of independent parameters, including the bottom slope of releasing free-surface flow tunnel downstream of service gate, the end top slope of pressure tunnel, the height of step, and the Froude number at take-off. During eight phases of experiments, the effects of above-mentioned parameters were observed on the cavity length downstream of the fully open operating service gate of a discharge tunnel. The results show that, the bottom slope of releasing free-surface flow tunnel has obvious effect on the cavity length as well as the Froude number at gate take-off. The effect of the step height variations on the cavity length could be considered for higher discharges and steeper tunnel top slope, particularly in higher discharges, resulting in shorter cavity length downstream of service gate.

关键词： cavitation erosion cavity length discharge tunnel service gate