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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 university,Taizhou 318000,{2. 2.Zhejiang water conservancy and hydropower College,Hangzhou 310018,{2. College of Physics and Electronics engineering Taizhou University Taizhou China Zhejiang water conservancy and {2. College Hangzhou 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

Analysis and application of the scale effect of flood discharge atomization model

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Science china(Technological Sciences) 2011年第S1期54卷 64-71页

作者： WU ShiQiang 1,WU XiuFeng 1,2.ZHOU Hui 1,CHEN HuiLing 1,SHA HaiFei 1 & ZHOU Jie 1 1 State Key Laboratory of Hydrology-water resources and Hydraulic engineering,{2. Hydraulic Research Institute,{2. 2.002.,china 2.hohai university,nanjing 2.0098,china State Key Laboratory of Hydrology-water resources and Hydraulic engineering Nanjing Hydraulic Research Institute Nanjing China hohai university Nanjing China

The phenomenon of discharge atomization occurs as hydraulic structures discharging,which influences the safety of power station,electrical equipment and produces environmental pollution.A series of physical model tests and feedback analysis are adapted to preliminarily study the scale effect of discharge atomization model by use of the field observation data of discharge *** effect of Re and We numbers of flow on the atomization intensity is analyzed.A conversion relationship of atomization intensity between prototype and model results and the similarity criteria of the atomization range are developed. The conclusion is that the surface tension of discharge atomization model could be ignored when the Weber number is larger than *** case studies are given by use of the similitude criteria of the atomization model.

关键词： discharge atomization scale effect energy dissipation model test feedback analysis

Dam risk assistant analysis system design

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Science china(Technological Sciences) 2008年第S2期51卷 101-109页

作者： HE XianFeng1,2.3,GU ChongShi3,4,WU ZhongRu3,4 & SU HuaiZhi3,4 1 Yellow River Institute of Hydraulic Research,Zhengzhou 450003,china 2.Embankment Security Defect Prevention and Control engineering Research Center of MWR,Zhengzhou 45000,china 3 College of water Resources and hydropower engineering,hohai university,nanjing 2.0098,china 4 National engineering Research Center of water Resources Efficient Utilization and engineering Safety,hohai university,nanjing 2.0098,china Yellow River Institute of Hydraulic Research Zhengzhou China Embankment Security Defect Prevention and Control engineering Research Center of MWR Zhengzhou China College of water Resources and hydropower {2. Hohai University Nanjing China National engineering Research Center of water Resources Efficient Utilization and engineering Safety Hohai University Nanjing China

In order to reduce the labor intensity and task difficulty of dam risk analysis and to meet the actual requirement of dam risk analysis,it is necessary to establish a dam risk assistant analysis *** program structure and the implementation ways of the dam risk assistant analysis system are analyzed,and a procedural framework with "three-tier and multi-database" structure and "level structure" is *** concept of dam risk assessment system modular development is proposed and the coupled mode of function module and data is ***,the dam risk assistant analysis system is developed using Delphi visual programming language.

关键词： dam risk risk analysis assistant analysis system

NUMERICAL MODELING PURIFICATION PERFORMANCE OF POT TEST

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Journal of Hydrodynamics 2010年第5期22卷 709-718页

作者： DAI Yu WANG De-guan ZHANG Jin-feng LUAN Qing-hua Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes of Ministry of Education Hohai University Nanjing 210098 China College of Mechanics and Materials Science Hohai University Nanjing 210098 China College of Environmental Hohai University Nanjing 210098 China College of water conservancy and {2. Hebei University of Engineering Handan 056021 China

A three-dimensional mathematical model was developed to simulate the pollutant removal efficiency of the soil and plants in the pot test. The advection, dispersion, diffusion, adsorption, biochemical reaction and plant uptake processes were taken into account in the model. The three-dimensional modified Richards equation was used in simulating flow field. The mass balance law was employed in deriving the equation for pollutant transport, where the diffusion and dispersion were described with the Fick-type law, the adsorption was macroscopically expressed as form isotherm, and the bio-chemical degradation process was assumed to follow the Monod kinetics. The mathematical model was descretized by the finite element numerical method. In the pot test, the hydraulic loading was assumed to have the intermittent pattern simulating the rainfall duration and the occurrence of frequency, and the concentrations of pollutants in the influent and effluent were measured. The computed overall removal rates for the CODCr and TN in four cases are in the range of 90.62. - 95.43% and 85.01% - 96.46%, respectively. The differences between the computed and tested overall removal rates for the CODCr and TN are smaller than 5%. The time-varying oscillation pattern of the concentrations of the CODCr and TN were rationally simulated, which showed that the model presented in this article could be used to assess the pollutant removal efficiency of the soil and plants in related cases.

关键词： pot test numerical modelling pollutant removal efficiency experiments

Temporal variation of suspended sediment load in the Pearl River due to human activities

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International Journal of Sediment Research 2011年第4期26卷 487-497页

作者： Wei ZHANG,Shousheng MU,Yanjing ZHANG,and Kaimin CHEN 1 Assoc.Prof.,State Key Laboratory of Hydrology-water Resources and Hydraulic engineering,{2., nanjing,2.0098,china, 2.4 Graduate student,College of Harbor,Coastal and Offshore engineering,{2.,nanjing,2.0098, china 3 Prof.,china Institute of water Resources and hydropower Research,Beijing,100038,china Assoc. Prof. State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University Nanjing 210098 China Graduate student College of Harbor Coastal and Offshore Engineering Hohai University Nanjing 210098 China Prof. China Institute of Water Resources and Hydropower Research Beijing 100038 China

Data on sediment flux at three hydrologic stations from the 1950s to 2.06 are utilized to study the decadal,annual,and monthly variations in suspended sediment load delivered from the Pearl River to the *** show that variations in sediment flux from three main tributaries,including the West River,the North River and the East River,are spatially *** nearly 90%of the suspended sediment load comes from the West River,its variation has dominated the overall tendency of sediment flux in the entire Pearl *** a significant decreasing trend exists in the annual variation of the total sediment flux,the decadal change can be divided into an increasing phase and a decreasing phase,with the turning point between the two phases in the late *** the 1950s to the 1980s,the average annual river sediment flux increased by 30.43%.However,sediment flux has decreased significantly since the 1990s,with the average sediment flux being 38.60%less in the 2.00s than that in the *** current sediment flux is also 52.93%less than its peak in the 1980s. The monthly variation pattern of the suspended sediment load transport to the sea is more interesting. For the West River,all months show a decreasing trend,and for most months the reduction values are ***,for the East River the sediment load shows a decrease trend in the dry season and an increase trend in the wet *** method of regression analysis was used to study the influence of precipitation in the variation on the sediment *** was found that the climate change is not the main driving force behind the variation in suspended sediment *** the 1990s, intensive land use destroyed the vulnerable ecosystem of the upper Pearl River,and speeded up the process of rocky ***,aggravated soil erosion caused an increase in suspended sediment ***,sediment retention within reservoirs had begun to play a dominant role after the massive constru

关键词： Pearl River Sediment flux Human activities Rocky desertification Dam construction

Decisive influence of the ionization strength of cosmic rays on the cavitation characteristics of pure water

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Science china(Technological Sciences) 2009年第6期52卷 1804-1808页

作者： CHANG JinShi College of water conservancy & Civil {2.,china Agricultural university,Beijing 100083,china College of water conservancy & Civil {2. China Agricultural University Beijing China

The experiment result in this article shows that the initial and critical cavitation pressure of pure water are both increasing along with the increase of height above sea level,and the ionization strength of cosmic rays in the lower aerosphere is the crucial factor which influences the cavitation pressure of pure *** author concludes the relationship between the cavitaion pressure of pure water and the height above sea ***,air particles in water caused by the radiation of cosmic rays can exist in the water for a long time and will not escape.

关键词： initial cavitaiton pressure critical cavitation pressure ionization strength of cosmic rays height above sea level

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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

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 {2. 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

Effects of Bahia Grass Cover and Mulch on Runoff and Sediment Yield of Sloping Red Soil in Southern china

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Pedosphere 2011年第2期21卷 238-243页

作者： LI Xin-Hu ZHANG Zhan-Yu YANG Jie ZHANG Guo-Hua WANG Bin College of water conservancy and {2. engineering Hohai University Nanjing 210098 (China) Key Laboratory of Efficient Irrigation-Drainage and Agricultural Soil hohai university Nanjing 210098 (China) Jiangxi Institute of Soil and water Conservation Nanchan9 330029 (China) china Irrigation and Drainage Development Center Beijing 100054 (China) College of water conservancy and Building {2. Northeast Agricultural University Harbin 150030 (China)

Rainfall,runoff (surface runoff,interflow and groundwater runoff) and soil loss from 5 m × 15 m plots were recorded for 5 years (2.01-2.05) in an experiment with three treatments (cover,mulch and bare ground) on sloping red soil in southern *** runoff and erosion from the Bahia grass (Paspalum notatum Flugge) cover plot (A) and mulch plot (B) during the 5 years were low,despite the occurrence of potentially erosive *** contrast,the bare plot (C) had both the highest surface runoff coefficient and the highest sediment *** were significant differences in interflow and surface runoff and no significant difference in groundwater runoff among *** runoff coefficients and duration of interflow and groundwater runoff were in the order plot B > plot A > plot *** of Bahia grass cover were excellent,indicating that the use of Bahia grass cover can be a simple and feasible practice for soil and water conservation on sloping red soil in the region.

关键词： groundwater runoff interflow lysimeter soil properties surface runoff