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THE UNITED METHOD FOR THE CALCULATION OF SEEPAGE CONTROL BY ADOPTING WEIGHTING SOIL LAYER ON THE BACK SIDE OF DIKE

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Journal of Hydrodynamics 2001年第4期13卷 92-97页

作者： Liu Chuan-shun, Yang Jin-zhong college of water {2. and Hydropower engineering, Wuhan university, Wuhan 430072. China Wuhan Univ. Wuhan 430072 China

Constructing a weighting soil layer at the downstream toe of dike on layered ground is an effective measure to prevent the foundation from blowout failures. In this paper, a series of differential equations describing the seepage flow in layered dike foundation were established, and a united method combining analytic method with one-dimensional finite difference method was proposed for solving the equations. The case study shows that the results calculated by the united method are considerably identical to the computational results of Finite Element Method (FEM), and the united method is very simple and easy compared to the FEM.

关键词： dike weighting soil layer seepage calculation seepage control united method

Detection of subcritical crack propagation for concrete dams

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Science China(Technological Sciences) 2009年第12期52卷 3654-3660页

作者： BAO TengFei1 ,2.YU Hong 1,2.1college of water {2.&Hydropower engineering,Hohai university,Nanjing 2.0098,China 2.ational engineering Research Center of water Resources Efficient Utilization and engineering Safety,Nanjing 2.0098,China college of water {2. & Hydropower engineering Hohai University Nanjing 210098 China National engineering Research Center of water Resources Efficient Utilization and engineering Safety Nanjing 210098 China

Subcritical propagation of cracks is a warning sign of *** such propagation is detected at an early stage,timely maintenance measures can be taken to prevent the failure of *** detect the subcritical propagation of a crack,the crack needs to be monitored continuously in a long term, which is not realistic under certain ***,cracks in concrete dams can be monitored continuously by dam monitoring to offer possible detection for subcritical *** this paper, with measured crack openings from dam monitoring,a state equation for characterizing crack development is established based on the grey system *** relation between the stability of the equation and the subcritical crack propagation is investigated,then a criterion is proposed for detecting subcritical *** example demonstrates the validity of the criterion and its potential for practical application.

关键词： crack subcritical propagation criterion concrete

A Dynamic Model for Simulating Atmospheric, Surface and Soil water interactions in Hillslope of Loess Area Under Natural Conditions and Its Application

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Pedosphere 2001年第3期11卷 271-282页

作者： ZHANG SHUHAN KANG SHAOZHONG CAI HUANJIE and NIE GUANGYONG Institute of Agricultural Soil-water engineering, Northwestern Agricultural {2., Yangling 712.00 (China) inner mongolia institute of water {6., Huhhot 01002. (China) Institute of Agricultural Soil-water engineering Northwestern Agricultural University inner mongolia Institute of {2. conservancy

The mechanism of atmospheric, surface and soil water interactions (water transformation) in hillslope under natural conditions was analyzed, and a dynamic model was developed to simulate infiltration, overland flow and soil water movement during natural rainfall in hillslope, by bringing forward concepts such. as rainfall intensity on slope and a correction coefficient of saturated soil water content for soil surface seal. Some factors, including slope angle, slope orientation and raindrop inclination, which affect the rainfall amount on slope, were taken into account while developing the dynamic model. The effect of surface seal on infiltration and water balance under a boundary condition of the second kind was also considered. Application of the model in a field experiment showed that the model simulated precisely the infiltration, overland flow and soil water movement in hillslope under natural rainfall conditions.

关键词： dynamic model hillslope infiltration soil water content water transformation

Effect of granular size on the angle of repose in the chute

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Science China(Physics,Mechanics & Astronomy) 2009年第4期52卷 563-565页

作者： ZHOU Ying1 & ZHANG GuoQin2.1 college of Physics and Electronics engineering,Taizhou {2.,Taizhou 318000,China 2.Zhejiang water conservancy and Hydropower college,Hangzhou 310018,China college of Physics and Electronics engineering Taizhou University Taizhou 318000 China Zhejiang water conservancy and Hydropower {2. Hangzhou 310018 China

Avalanche in the chute has been studied to examine how the sizes of granules affect the angle of repose θr when the width of the chute is fixed. The results show that the angle of repose in the chute has exponential decay with λ,which is the reciprocal of granular diameter d. The fluctuation of the angle of repose is also studied during the chute being tilted,and the results indicate that the fluctuation of the angle of repose increases with the increase of granular diameter d.

关键词： Granular matter avalanche the angle of repose granular diameter

Assessment model of dam operation risk based on monitoring data

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Science China(Technological Sciences) 2007年第z1期50卷 144-152页

作者： WU ZhongRu1,2., SU HuaiZhi1,2.& GUO HaiQing1 1 college of water {2. and Hydropower engineering, Hohai university, Nanjing 2.0098, China 2.National engineering Research Center of water Resources Efficient Utilization and engineering Safety, Nanjing 2.0098, China 1. college of water {2. and Hydropower engineering Hohai University Nanjing 210098 China 2. National engineering Research Center of water Resources Efficient Utilization and engineering Safety Nanjing 210098 China

Although the dams produce remarkable social and economic benefits, the threat made by unsafe dams to the life and property of people who live in the lower river area is un-negligible. Based on the monitoring data which reflect the safety condition of dams, the risk degree concept is proposed and the analysis system and model for evaluating risk degree (rate) are established in this paper by combining the reliability theory and field monitoring data. The analysis method for risk degree is presented based on Bayesian approach. A five-grade risk degree system for dam operation risk and corresponding risk degree is put forward according to the safety condition of dams. The operation risks of four cascade dams on some river are analyzed by the model and approach presented here and the result is adopted by the owner.

关键词： dam monitoring data operation risk degree analysis model

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 {2. and Hydropower 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 {2. and Hydropower engineering Hohai University Nanjing 210098 China National engineering Research Center of water Resources Efficient Utilization and engineering Safety Nanjing 210098 China Department of Computer engineering Nanjing Institute of Technology Nanjing 210013 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

Field experiments on greenhouse gas emissions and nitrogen and phosphorus losses from rice paddy with efficient irrigation and drainage management

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Science China(Technological Sciences) 2011年第6期54卷 1581-1587页

作者： PENG ShiZhang1,2.YANG ShiHong1,2.XU JunZeng1,2.& GAO HuanZhi1,2.1State Key Laboratory of Hydrology-water Resources and Hydraulic engineering,Hohai {2.,Nanjing 2.0098,China 2.3} of water conservancy and Hydropower engineering,Hohai {2.,Nanjing 2.0098,China 1. State Key Laboratory of Hydrology-water Resources and Hydraulic engineering Hohai University Nanjing 210098 China2. College of Water Conservancy and Hydropower Engineering Hohai University Nanjing 210098 China

Greenhouse gas emissions,nitrogen and phosphorous losses through ammonia volatilization,leaching and surface drainage from rice paddy under efficient irrigation and drainage were analyzed based on field experimental data in order to reveal the eco-environmental impacts of efficient irrigation and drainage on rice *** results showed that total methane emission from rice paddy under the controlled irrigation was reduced by more than 80% and total nitrous oxide emission increased by 15.9% compared with flooding *** comprehensive global warming potentials(GWP) of methane and nitrous oxide were 6..2. gCO2.m-2.for rice paddy under the controlled irrigation,reduced by 6..0% compared with flooding *** to large reduction in seepage and surface drainages,nitrogen and phosphorous losses through leaching were reduced by 40.1% and 54.8%,nitrogen and phosphorous losses through surface drainage were reduced by 53.9% and 51.6. from rice paddy under efficient irrigation and drainage compared with traditional irrigation and *** loss through ammonia volatilization was reduced by 14.0%.Efficient irrigation and drainage management is helpful to mitigate greenhouse gases emission,nitrogen and phosphorus losses and their pollution on groundwater and surface water.

关键词： efficient irrigation and drainage nitrogen and phosphorus greenhouse gas ammonia volatilization paddy field

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 {2.,Nanjing 2.0098,China 2.3} of water conservancy Hydropower,Hohai {2.,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 1. State Key Laboratory of Hydrology-water Resources and Hydraulic engineering Hohai University Nanjing 210098 China2. College of Water Conservancy Hydropower Hohai University Nanjing 210098 China3. National Engineering Research Center of Water Resources Engineering Safety Efficient Utilization and Nanjing Nanjing 210098 China4. Nanjing Hydraulic Research Institute Nanjing 210029 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

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 {2. and Hydropower engineering,Hohai university,Nanjing 2.0098,China college of water {2. and Hydropower engineering Hohai University Nanjing 210098 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