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Science china(Technological Sciences) 2011年第4期54卷 793-798页

作者： bao tengfei1,2.3,xu baosong1,2.3 & zheng xueqing1,2.3 1state key laboratory of hydrology-water resources and hydraulic engineering,hohai university,nanjing 2.0098,china 2National engineering Research Center of water resources Efficient Utilization and engineering Safety,nanjing 2.0098,china 3College of water Conservancy and Hydropower engineering,hohai university,nanjing 2.0098,china state key laboratory of hydrology-water resources and hydraulic engineering Hohai University Nanjing China National engineering Research Center of water resources Efficient Utilization and engineering Safety Nanjing China College of water Conservancy and Hydropower engineering Hohai University Nanjing China

A hybrid method of limit equilibrium and finite element internal force for analysis of arch dam stability against sliding is *** finite element internal force method(FEIFM) is used to provide more accurate thrust forces acting on the faces of a slip body,and the limit equilibrium method(LEM) is employed to evaluate the factor of safety of the slip *** method presented can deal with a slip body with large amount of geometrically complex slip *** addition,compared with the traditional LEM,it can meet the balance condition of the forces in the slip *** example shows that the factor of safety obtained by the method presented agrees well with the theoretical solution.A practical example is also presented to demonstrate the application of the method in the stability analysis of an arch dam *** results from the examples show that the method is promising in analysis of arch dam stability against sliding.

关键词： arch dam stability against sliding limit equilibrium method finite element internal force method

Multivariate analysis in dam monitoring data with PCA

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Science china(Technological Sciences) 2010年第4期53卷 1088-1097页

作者： YU Hong1,2,WU ZhongRu1,2,bao tengfei1,2 & ZHANG Lan1,2 1 state key laboratory of hydrology-water resources and hydraulic engineering,hohai university,nanjing 2.0098,china 2 National engineering Research Center of water resources Efficient Utilization and engineering Safety,hohai university,nanjing 2.0098,china state key laboratory of hydrology-water resources and hydraulic engineering Hohai University Nanjing China National engineering Research Center of water resources Efficient Utilization and engineering Safety Hohai University Nanjing China

Given the limitation of traditional univariate analysis method in processing the multicollinearity of dam monitoring data,this paper reconstructs the multivariate response variables by introducing principal component analysis(PCA) method,explores the ways of determining principal components(PCs),and extracts a few PCs that have major influence on data *** steady observation series,a control field for the whole observation values has been established based upon PCA;for unsteady observation series that have significant tendency,a control field for the future observation values has been constructed according to PC statistical predication *** methods have already been applied to an actual project and the results showed that data interpretation method with PCA can not only realize data reduction,lower data redundancy,and reduce noise and false alarm rate,but also be effective to data analysis,having a broad application prospect.

关键词： dam safety monitoring multivariate response variables principal component analysis data reduction

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 university,nanjing 2.0098,china 2College of water Conservancy and Hydropower engineering,hohai university,nanjing 2.0098,china state key laboratory of hydrology-water resources and hydraulic engineering Hohai University Nanjing China College of water Conservancy and Hydropower engineering Hohai University Nanjing 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 62.23 gCO2 m-2 for rice paddy under the controlled irrigation,reduced by 68.0% 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

Analysis of crack propagation in concrete structures with structural information entropy

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Science china(Technological Sciences) 2010年第7期53卷 1943-1948页

作者： bao tengfei1’2, PENG Yan1’2, CONG PeiJiang1’2 & WANG JiaLin1’2 1 state key laboratory of hydrology-water resources and hydraulic engineering, hohai university, nanjing 210024, china 2 National engineering Research Center ofwater resources Efficient Utilization and engineering Safety, hohai university, nanjing 210024, china state key laboratory of hydrology-water resources and hydraulic engineering Hohai University Nanjing China National engineering Research Center of water resources Efficient Utilization and engineering Safety Hohai University Nanjing China

The propagation of cracks in concrete structures causes energy dissipation and release, and also causes energy redistribution in the structures. Entropy can characterize the energy redistribution. To investigate the relation between the propagation of cracks and the entropy in concrete structures, cracked concrete structures are treated as dissipative structures. Structural information entropy is defined for concrete structures. A compact tension test is conducted. Meanwhile, numerical simulations are also carried out. Both the test and numerical simulation results show that the structural information entropy in the structures can characterize the propagation of cracks in concrete structures.

关键词： crack entropy concrete sun

Experimental study on three dimensional movements of particles Ⅱ Effects of particle diameter on turbulence characteristics

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International Journal of Sediment Research 2009年第2期24卷 169-176页

作者： Limo TANG1 and Xingkui WANG2 1state key laboratory of hydrology-water resources and hydraulic engineering,hohai university, nanjing 2.0098,china 2 Prof.,state key laboratory of Hydroscience and engineering,Tsinghua university,Beijing 100084,china state key laboratory of hydrology-water resources and hydraulic engineering Hohai University Nanjing 210098 China state key laboratory of Hydroscience and engineering Tsinghua University Beijing 100084 China

Based on the 3D PTV(Particle Tracking Velocimetry) measuring system,the 3D movement characteristics of particles with four different diameters were investigated. Under specific flow conditions,the impact of particle diameters on 3D motion of particles was studied,and the turbulence characteristics were analyzed by different statistical methods. The results showed that the turbulence intensity of coarse particle decreased as the diameter increased. In near wall region,the probability density distributions of longitudinal and vertical fluctuation velocities both deviated from the normal distribution;while in the outer region,the probability density distribution of vertical fluctuation velocity approximately agreed with the normal distribution.

关键词： Particle diameter Turbulence Probability density distribution

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 2College 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 210029,china state key laboratory of hydrology-water resources and hydraulic engineering Hohai University Nanjing China College of water Conservancy Hydropower 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

Activation of fly ashes by the high temperature and high alkalinity in ASR tests

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Science china(Technological Sciences) 2011年第S1期54卷 28-32页

作者： CAI YueBo ,DING JianTong & BAI Yin state key laboratory of hydrology-water resources and hydraulic engineering,nanjing hydraulic Research Institute,nanjing 210029,china state key laboratory of hydrology-water resources and hydraulic engineering Nanjing Hydraulic Research Institute Nanjing China

High temperature and high alkalinity are typical testing conditions to accelerate the appraisal process of the suppressing effect of fly ashes on alkali silica reaction(ASR),but the reaction mechanism of fly ashes would be quite different under such conditions compared to the normal condition of temperature and *** make a reasonable analysis of the suppressing effect of fly ashes,13 types of fly ashes were tested in this paper by both the accelerated mortar bar test method and the 60°C accelerated concrete prism test *** results showed that the effect of fly ashes would be magnified under the condition of high temperature and high *** XRD analysis showed that all the phases of fly ash could react with the hot alkaline solution except for mullite and a small amount of *** ash could be significantly activated by the 80°C 1 mol/L NaOH solution,and form mainly C-S-H phase and P type zeolite,but its effect on inhibiting ASR was exaggerated *** to the mortar strength test and the ASR suppressing test results,C-S-H phase contributed to mortar strength,but its amount did not decide the ASR suppressing effect of fly ash.

关键词： fly ash Alkali silica reaction Activation

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,nanjing hydraulic Research Institute,nanjing 210029,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

Damage and progressive failure of concrete structures using non-local peridynamic modeling

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Science china(Technological Sciences) 2011年第3期54卷 591-596页

作者： HUANG Dan1,2, ZHANG Qing1,2 & QIAO PiZhong1,3 1 state key laboratory of hydrology-water resources and hydraulic engineering, hohai university, nanjing 2.0098, china 2 Department of engineering Mechanics, hohai university, nanjing 2.0098, china 3 Department of Civil and Environmental engineering, Washington state university, Pullman, WA 99164-2910, USA state key laboratory of hydrology-water resources and hydraulic engineering Hohai University Nanjing China Department of engineering Mechanics Hohai University Nanjing China Department of Civil and Environmental engineering Washington State University Pullman USA

Peridynamics (PD), a recently developed theory of solid mechanics, which employs a non-local model of force interaction and makes use of integral formulation rather than the spatial partial differential equations used in the classical continuum mechanics theory, has shown effectiveness and promise in solving discontinuous problems at both macro and micro scales. In this paper, the peridynamics theory is used to analyze damage and progressive failure of concrete structures. A non-local peridynamic model for a rectangular concrete plate is developed, and a central pairwise force function is introduced to describe the interior interactions between particles within some definite distance. Damage initiation, evolution and crack propagation in the concrete model subject to in-plane uni-axial tension, in-plane uni-axial compression and out-of-plane impact load are investigated respectively. The numerical results show that discontinuities appear and grow spontaneously as part of the solution to the peridynamic equations of motion, and no special failure criteria or re-meshing techniques are required, which proves the potential of peridynamic modeling as a promising technique for analyzing the progressive failure of concrete materials and structures.

关键词： concrete damage progressive failure peridynamic model discontinuities

Application analysis of empirical mode decomposition and phase space reconstruction in dam time-varying characteristic

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Science china(Technological Sciences) 2010年第6期53卷 1711-1716页

作者： ZHANG ZhiJun1,2.3,GU ChongShi1,2,bao tengfei1,2,ZHANG Lan1,2 & YU Hong1,2 1 state key laboratory of hydrology-water resources and hydraulic engineering,hohai university,nanjing 2.0098,china 2 National engineering Research Center of water resources Efficient Utilization and engineering Safety,hohai university,nanjing 2.0098,china 3 Department of Civil,Environmental and Geomatic engineering,Swiss Federal Institute of Technology,Zurich 8093,Switzerland state key laboratory of hydrology-water resources and hydraulic engineering Hohai University Nanjing China National engineering Research Center of water resources Efficient Utilization and engineering Safety Hohai University Nanjing China Department of Civil Environmental and Geomatic Engineering Swiss Federal Institute of Technology Zurich Switzerland

In view of some courses of the time-varying characteristics processing in the analysis of dam deformation,the paper proposes a new method to analyze the dam time-varying characteristic based on the empirical mode decomposition and phase space reconstruction *** of all,to reduce the influences on the traditional statistical model from human factors and assure the analysis accuracy,response variables of the time-varying characteristic are obtained by the way of the empirical mode decomposition;and then,a phase plane of those variables is reconstructed to investigate their processing *** methods have already been applied to an actual project and the results showed that data interpretation with the assists of empirical mode decomposition and phase space reconstruction is effective in analyzing the perturbations of response variables,explicit in reflecting the entire development process,and valid for obtaining the evolution rules of the time-varying *** methodology is a powerful technical support for people to further master the rules of dam operation.

关键词： dam safety monitoring dam time-varying characteristic empirical mode decomposition phase space reconstruction