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土石坝震害与抗震安全

水力发电学报 2011年第6期30卷 40-51页

作者：朱晟河海大学水文水资源与水利水电工程科学国家重点实验室南京210098 河海大学水电学院南京210098

结合世界上地震区已建土石坝的震害调查,对主要震害型式、产生机理以及防止震害的对策进行了剖析,分析了现代碾压式高土石坝抗震性能优良的内在原因。从设防标准、抗震能力与抗震风险以及坝体填筑设计质量控制指标等方面论证了现阶段强... 详细信息

结合世界上地震区已建土石坝的震害调查,对主要震害型式、产生机理以及防止震害的对策进行了剖析,分析了现代碾压式高土石坝抗震性能优良的内在原因。从设防标准、抗震能力与抗震风险以及坝体填筑设计质量控制指标等方面论证了现阶段强震区高土石坝建设需重视的问题。在深入开展土石坝抗震理论研究的基础上,适当提高坝料填筑设计指标以控制有害变形,强震区300m级高土石坝的建设是安全可行的。

关键词：地震土石坝液化滑坡永久变形

DYNAMIC CORRECTION OF ROUGHNESS IN THE HYDRODYNAMIC MODEL

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Journal of Hydrodynamics 2009年第2期21卷 255-263页

作者： BAO Wei-min ZHANG Xiao-qin QU Si-min State Key Laboratory of Hydrology-water resources and Hydraulic engineering College of Hydrology and Water Resources Hohai University Nanjing 210098 China

Based on the hydrodynamic model and the Xinanjiang model, the fiver stage forecasting model has been proposed. But its performance is not satisfactory as applied to estuary areas. River roughness is a sensitive parameter in the hydrodynamic model, and its value is related to some substantial uncertainties in the tidal fiver. According to roughness tests, a new method of roughness dynamic correction was developed to improve the performance of the stage model. The method was focused on the usage of observed data for the studied section, and its parameters were analyzed. Nested with the dynamic correction of roughness, the stage model was applied to the tidal reach of the Caoe River. The results demonstrate that the roughness dynamic correction can improve the simulation accuracy of the stage model, and especially has the capacity of reducing the errors at peak stages.

关键词： hydrodynamic model Xinanjiang model roughness test roughness dynamic correction nesting-modeling Caoe River

Spectral wave transformation model for simulating refrac-tion-diffraction with strongly reflecting coastal structures

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Acta Oceanologica Sinica 2011年第2期30卷 25-32页

作者： ZHENG Jinhai NGUYEN Viet Thanh ZHANG Chi State Key Laboratory of Hydrology-water resources and Hydraulic engineering HohaiUniversity Nanjing 210098 China college of Harbor Coastal and Offshore engineering Hohai University Nanjing 210098 China

On the basis of the wave action balance equation which incorporates refraction,diffraction,reflection and wave-current interaction,a directional spectral wave transformation model WABED is developed for predicting the irregular wave refraction-diffraction with strongly reflecting structures in coastal *** the model,diffraction is taken into account by introducing a term formulated from a parabolic approximation wave equation,and reflection is calculated through a back-marching numerical approach at the reflecting *** experimental data sets are used to examine the performance of present model with regard to wave characteristics around reflecting coastal *** is from a physical experiment at idealized inlet with parallel jetties,while the other is from a laboratory study on a coastal project of the concave *** good agreements are found for both cases,revealing the applicability of the present model for predicting combined wave refraction-diffraction processes with strongly reflecting coastal structures.

关键词： Wave Height Coastal Structure Spectral Wave Wave Prediction Spectral Wave Model

THE ROLE FORE AIR FLOW IN SOIL SLOPE STABILITY ANALYSIS

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Journal of Hydrodynamics 2009年第5期21卷 640-646页

作者： ZHANG Xiao-yue ZHU Yue-ming FANG Chun-hui college of water Conservancy and hydropower engineering Hohai University Nanjing 210098 China

In order to investigate the effect of the pore air flow in the soil slope stability analysis, a water-air two-phase flow model, based on the multi-phase flow theory, is proposed and with the model, the water-phase and air-phase seepages of the soil slope in the stable seepage and rainfall situations are simulated. The soil slope safety coefficients are obtained according to the simulated pore air pressure and pore water pressure. The calculation results show that in the stable seepage situation, the influence of the pore air pressure on the soil slope stability can be neglected, while in the rainfall situation, the pore air pressure generated in the unsaturated zone will reduce the safety coefficient, and the larger the distance between the slip surface and the underground water level is, the greater the influence of the pore air pressure on the soil slope stability will be.

关键词： unsaturated soil water-air two-phase flow rainfall slope stability

Fuzzy Comprehensive Evaluation for Decision Making of water Saving Irrigation System

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Wuhan University Journal of Natural Sciences 2003年第3A期8卷 837-841页

作者： Luo Jin\|yao, Qiu Yuan\|feng college of water resources and hydropower engineering , Wuhan University, Wuhan 430072, Hubei, china Wuhan University College of Water Resources and Hydropower Engineering Wuhan Hubei China (GRID:grid.49470.3e) (ISNI:***)

A model of fuzzy comprehensive evaluation for water saving irrigation system (WSIS) decision making is proposed based on establishing an index system affected by six kinds of basic factors including qualitative and quantitative indexes. The object function of WSIS is set up by using the concept of fuzzy membership degree, it is to transform characteristic vector matrix into unify membership matrix and extending the least square method to the least of weighted distance square. The optimum weighted membership degree and the inferior weighted membership degree are used to solve the object function. This method effective solves the problem of classify for fuzzy attributive indexes and the problem of optimum for the set of different attributive indexes. A case study shows that the fuzzy comprehensive evaluation model is reasonable and effective in decision making for water saving irrigation system planning.

关键词： water saving irrigation system (WSIS) decision making fuzzy comprehensive evaluation (FCE) index system fuzzy membership degree

Influence of the impounding process of the Three Gorges Reservoir up to water level 172.5m on water eutrophication in the Xiangxi Bay

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Science china(Technological Sciences) 2010年第4期53卷 1114-1125页

作者： YANG ZhengJian1,LIU DeFu1,JI DaoBin1,2 & XIAO ShangBin1,3 1 college of Civil & Hydroelectric engineering,china Three Gorges University,Yichang 443002,china 2 School of water resources & hydropower engineering,Wuhan University,Wuhan 430072,china 3 Institute of Earth Environment,Chinese Academy of Sciences,Xi’an 710075,china 1. college of Civil & Hydroelectric engineering China Three Gorges University Yichang 443002 China2. School of Water Resources & Hydropower Engineering Wuhan University Wuhan 430072 China3. Institute of Earth Environment Chinese Academy of Sciences Xi’an 710075 China

The water level of the Three Gorges Reservoir(TGR) rose to 172.5 m in two stages from September to November,*** hydrodynamic parameters and water quality parameters(*** velocity,temperature,turbidity and nutrient content) had been continuously monitored to reveal the influence of the impounding process of the TGR on the water eutrophication in the Xiangxi Bay(XXB).The maximal daily rise of the water level of the TGR was about 2.38 *** water exchange between the mainstream(the Changjiang River) and the XXB of the TGR was enhanced by density current,and its main characteristics were a density-stratified flow in different *** water exchange reduced the differences of the water quality parameters(for example,temperature,turbidity,nutrient level,pH,etc.) between the mainstream and the XXB during the impounding ***,the water stability index in the mainstream remained small but it was lowered in the *** main causes included the dilution by water of lower concentration of the chlorophyll a(Chl.a) entering from the mainstream,the decline of the water stability,and the increase of suspended silt,which induced the Chl.a to decrease in the XXB during the impounding *** grade of the water eutrophication changed from middle eutrophic level to mesotrophic state in the ***,as available nutrients were imported into the XXB from the mainstream during the impounding process the risk of water eutrophication increases in the XXB in the future.

关键词： impounding density current eutrophication the Xiangxi Bay the Three Gorges Reservoir

EXPERIMENT OF IMPACT OF RIVER HYDRAULIC CHARACTERISTICS ON NUTRIENTS PURIFICATION COEFFICIENT

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Journal of Hydrodynamics 2007年第3期19卷 387-393页

作者： WANG Pei-fang WANG Xiao-rong WANG Chao State Key Laboratory of Pollution Control and Resource Reuse School of Environment Nanjing University Nanjing 210093 China State Key Laboratory of Hydrology-water resources and Hydraulic engineering Hohai University Nanjing 210098 China Key Laboratory of Intergrated Regulation and Resource Development on Shallow Lakes College of Environmental Science and Engineering Hohai University Nanjing 210098 China

Hydraulic characteristics of a river are the key factors for river water quality improvement and river restoration. A simulated river was exploited to study the interactions between water contaminant purification coefficients and the characteristics of the river, such as the cross-section velocity, water depth, Reynolds number, and Froude number. To enhance the purification capacity of the river, detritus with 5 mm to 10 mm in diameter and contact surface area per volume of 87.6 m^2/m^3 were constructed naturally at the bed and along one side of the bank to form half shape of the river cross-section. During the one-month experiment （including 3 periods） from the third of November to the fourth of December, 2005, three categories of hydraulic conditions were investigated. Results show that the purification coefficient （K） of Total Nitrogen （TN） is closely coherent with the hydraulic retention time （T）, river length （L）, Reynolds number （Re） and Froude number （Fr）. The relationship of K and T generally agrees with the power law under the three experimental water hydraulic conditions. Based on these results, the optimal Re and Fr ranges can be obtain to serve as a guideline for ecological re-engineering design to improve river water quality and restore river ecosystem.

关键词： Hydraulic characteristics total nitrogen,purification coefficient interaction simulated river

TWO DIMENSIONAL SIMULATION OF WIND-DRIVEN CIRCULATION IN RESERVOIR

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Journal of Hydrodynamics 2003年第3期15卷 112-118页

作者： ChenJie-ren KhalilI.Othman collegeofwaterresourcesandEnvironment HohaiUniversityNanjing210098China collegeofEnvironmentengineering HohaiUniversityNanjing210098China

The development of a simplified 2-D numerical model was described forwind-driven circulation in reservoir u-sing standard k-ε turbulence model to specify eddy viscositydistribution. The governing equations are transformed and solved on variable vertical grids, whichallows refinement at the surface and bottom boundaries. The results of the model simulation for floware compared with analytical solutions for laminar and turbulent flows, experimental data in awind-flume and wind wave tank. The sensitivity analysis results show that use of large number ofdepth layers increases the accuracy for the bottom counter-current flow. Prediction of surface driftwas not very sensitive to surface grid refinement. The model was also applied to Baisha reservoirfor an assumed wind condition and showed to be able to simulate the general features of surfacedrift and return flow under variable flow depth. The model can serve as alternative means ofstudying wind-driven flow beside experiments. It also reduced the problem complexity associated with3-D circulation models while faithfully reproducing the drift and near bottom return currents.

关键词： mathematical modeling wind-driven circulation surface drift countercurrent flow

ON NECESSITY OF PLACING AN AERATOR IN THE BOTTOM DISCHARGE TUNNEL AT THE LONGTAN hydropower STATION

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Journal of Hydrodynamics 2006年第6期18卷 698-701页

作者： WU Jian-hua WU Wei-wei RUAN Shi-ping college of water Conservancy and hydropower engineering Hohai University Nanjing 210098 China

The air entrainment for avoiding cavitation damage has been widely used in long free flow tunnels. It is crucial to determine whether an aerator is needed for shorter tunnels. In this article, the bottom discharge tunnel at the Longtan hydropower Station was involved, for which the free flow tunnel section was only 50.00 m long. The cavitation in the tunnel with and without the aerator was investigated using the physical models of the scale 1/30, through the measurements of cavitation noise. The experimental results show that it is necessary to place the aerator at the inlet of the free flow section for higher reservoir level to protect this tunnel from cavitation damage.

关键词： aerator bottom discharge tunnel cavitation damage cavitation noise Longtan hydropower Station