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Research on forecasting model of sandstone deformation rate during sine wave loading segment under the lag effect

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Science china(Technological Sciences) 2010年第5期53卷 1442-1449页

作者： LIU Jie1,2.LI JianLin1,2.QU JianJun1,ZHOU JiFang3,ZHANG ChaoFeng3 & LI JianWu1 1Key Laboratory of Geological Hazards on three gorges Reservoir Area,Ministry of Education,{2. three gorges University,yichang 443002.{2. 2.ollege of Civil and Hydropower Engineering,{2. three gorges University,yichang 443002.{2. 3Er’tan Hydropower Development Company,Ltd.Chengdu 61000,{2. 1. Key Laboratory of Geological Hazards on three gorges Reservoir Area Ministry of Education China Three Gorges University Yichang 443002 China2. College of Civil and Hydropower Engineering China Three Gorges University Yichang 443002 China3. Er’ tan Hydropower Development Company Ltd. Chengdu 61000 China

To reduce data variance caused by individual differences of different samples,a new experimental method is proposed by loading and unloading the axial forces with different frequencies and different waves of a certain load amplitude to the same rock sample without damaging *** time segments are defined and fractionized into segments I and Ⅱ.Criterions for seg-mentation,definitions of relevant parameters and empirical analysis are also offered *** the course of sinusoidal loading,the serious peak value dislocation of the displacement variation rate and the loading rate is defined as peak ***,the definition of the apparent tangent modulus is put forward and the linear relation between it and the vertical force in the frequency of 0.1,0.2.0.5 Hz sinusoidal loading segment is confirmed to be ever-present on the basis of the test *** the calculating formula of the deformation rate in non-lag time is *** is thus suggested that the deformation rate should be codetermined by the loading rate df/dt and instant load f(t),which well explains the peak dislocation of the time-variable curve peak value of dl/dt and deformation rate of df/*** the lag time derivation model is established and by comparing the calculated values with the measured ones,it is demonstrated that the above formula offers a better simulation of the sandstone deformation rate in the sinusoidal loading segment,with the load amplitude being 96 kN and the frequency ranging from 0.1 Hz to 0.5 Hz.

关键词： lag time segments peak shifting phenomenon apparent tangent modulus deformation rate

Coupling analysis of unsteady seepage and stress fields in discrete fractures network of rock mass in dam foundation

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Science china(Technological Sciences) 2011年第S1期54卷 133-139页

作者： CHAI JunRui 1,2.& XU WeiSheng 2.1 College of Hydraulic and Environmental Engineering,china three {2. University,yichang 443002.china 2.College of Hydropower Engineering,Xi’an University of Technology,Xi’an 710048,china 1. College of Hydraulic and Environmental Engineering China Three Gorges University Yichang 443002 China2. College of Hydropower Engineering Xi’an University of Technology Xi’an 710048 China

The drag force of water flow through single fracture and the coupling characteristics of seepage and stress in single fracture surface are analyzed,and a three dimensional model of coupled unsteady seepage and stress fields is *** model is used to the analysis of foundation rock mass of a high *** the coupling effects are considered,the changes of boundary heads have less influence on the inner head of rock mass,and the strong permeability of main fractures *** the coupling effects are not considered,the fractures distribution affects the inner head more *** the upstream water head declines,the inner head of dam foundation slightly declines and the hydraulic gradient distribution becomes smoother.A bigger upstream water level declining velocity has a stronger lag effect,meanwhile the values of stress components change more *** the upstream water level declining velocity directly affects the stability of rock mass in dam foundation and we should take into account the above factors to make sure the safety of the dam during reservoir level fluctuation period.

关键词： hydraulic engineering unsteady seepage stress coupling fractures network rock mass

Incipient Motion of Bed Load Sediment and Its Application in the three gorges Hydro Project

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四川大学学报（工程科学版） 2005年第S1期37卷 102-105页

作者： HE Wenshe~(1,3) CAO Shuyou~2.YUAN Jie~3 DAI Huichao~3 (1.Lanzhou Jiao Tong Univ.,Lanzhou 730070,china 2.State Key Lab.of Hydraulics and Mountain River Eng.,Sichuan Univ.,Chengdu 610065,china 3.china Yangtze three gorges Project Development corporation,Hubei yichang 443002.china) Lanzhou Jiaotong Univ. Lanzhou 730070 China china Yangtze three {2. Project Development corporation Yichang 443002 China State Key Lab. of Hydraulics and Mountain River Eng. Sichuan Univ. Chengdu 610065 China

A formula for the calculation of critical shear stress of non-uniform sediment was developed by on river bed has been established while considering the relative degree expose of *** values of the Coeffi- cients in the formula have been *** formula has been verified with prototype observation data, flumes data of both nature and lightweight *** computed results fully reflect the characteristics of thresh- old motion of non-uniform *** result have been used in some physical mo...

关键词： non-uniform sediment incipient motion bed load three gorges Hydro Project

Anisotropic damage coupled modeling of saturated porous rock

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Science china(Technological Sciences) 2010年第10期53卷 2681-2690页

作者： LU YingFa1,2. WU XinXing1,2.& SHAO JianFu3 1 Key Laboratory of Geological Hazards on three gorges Reservoir Area, Ministry of Education, {2. three gorges University, yichang 443002. {2. 2.School of Civil Engineering, Wuhan University, Wuhan 430071, {2. 3 University of Sciences and Technologies of Lille, Lille 59655, France 1. Key Laboratory of Geological Hazards on three gorges Reservoir Area Ministry of Education China Three Gorges University Yichang 443002 China2. School of Civil Engineering Wuhan University Wuhan 430071 China3. University of Sciences and Technologies of Lille Lille 59655 France

It is widely acknowledged that the natural rock mass is anisotropic and its failing type is also non-isotropic. An orthotropic elastic damaged model has been proposed in which the elastic deformation,the damaged deformation and irreversible deformation can be identified respectively. A second rank damage tensor is employed to characterize the induced damage and damage evolution related to the propagation conditions of microcracks. A specific form of the Gibbs free energy function is used to obtain the effective elastic stiffness and the limited scopes of damage parameters are suggested. The model’s parameter determination is proposed by virtue of conventional tri-axial test. Then,the proposed model is developed to simulate the coupled hydraulic mechanical responses and traction behaviors in different loading paths of porous media.

关键词： anisotropy damage modeling saturated rock tensile failure

Daily optimized model for long-term operation of the three gorges-Gezhouba Cascade Power Stations

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Science china(Technological Sciences) 2007年第z1期50卷 98-110页

作者： CAO GuangJing1, CAI ZhiGuo1?, LIU ZhiWu1 & WANG GuangQian2.1 china three {2. Project corporation, yichang 443002. china 2.State Key Laboratory of Hydroscience and Engineering, Tsinghua University, Beijing 100084, china china three {2. Project corporation Yichang 443002 China State Key Laboratory of Hydroscience and Engineering Tsinghua University Beijing 100084 China

This paper presents the step-by-step genetic algorithm based on artificial intelligence guidance and builds a long-term daily optimized operating model for the three gorges-Gezhouba Hydropower Complex with single generating set as the based operating unit. Actual operating data from 2.04 to 2.06 are used to verify the model, and results show that the simulation accuracy determined by measuring the total amount of cascade power generation reaches 99.66%. Statistic hydrological data of normal years and actual data of three years of 2.04―2.06 are respectively used to perform an optimized prediction of the power generation process and benefits in future when the water stored in the TGP Reservoir reaches 175 m level and power generation benefits under different operation modes, such as delayed subsiding water level, advance water storage, and adopting of different flood-limited water levels, are forecasted. In the case of years with normal inflows, the total amount of cascade power generation running on current specifications reaches 107500 GWh per year. If the commencement of water storage after the flood season is moved forward by 2. days, the amount of power generation can be increased by 3400 GWh per year. If the limited water level in the flood season is raised by three to five meters, the amount of power generation can be increased by 1600 to 32.0 GWh per year. If the commencement of water storage is moved forward while the maximum water level allowed in the flood season is raised, the amount of power generation can be increased by 6400 GWh per year.

关键词： cascade operation three gorges Project genetic algorithm optimization forecast

Numerical simulation of two-phase turbulent flow in hydraulic and hydropower engineering

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Science china(Technological Sciences) 2007年第z1期50卷 79-89页

作者： DAI HuiChao1,2., WANG LingLing1, GAO JiZhang3, ZHANG XiaoDong3 & YANG ZhongHua2.1 College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing 2.0098, china 2.china Yangtze River {2. gorges Project Development corporation, yichang 443002. china 3 china Institute of Water Resources and Hydropower Research, Beijing 100044, china College of Water Conservancy and Hydropower Engineering Hohai University Nanjing 210098 China china Yangtze River three {2. Project Development corporation Yichang 443002 China china Institute of Water Resources and Hydropower Research Beijing 100044 China

In connection with the specific features of high velocity aerated flow generated by hydraulic engineering structures, the mathematical model is developed for high turbulence air-water two-phase flow with the use of twin flow theoretical model in this paper. Furthermore the numerical method is proposed to treat bubbled flows. In addition, on the basis of air-water stratified twin flow model, the new calculation methods and free surface tracking technique are proposed to describe complicated movements of the free surface. Finally, the proposed model is used to calculate artificial aerated flows. The computed results coincide quite well with experimental results. This means that the proposed method can provide solid basis for practical engineering design.

关键词： high turbulence two-phase flow twin flow model aerated flow free surface

The feature study on the π and proton rapidity distributions at AGS, SPS and RHIC

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Science china(Physics,Mechanics & Astronomy) 2009年第2期52卷 198-206页

作者： FENG ShengQin1,2.& YUAN XianBao1,3 1 College of Science, china three {2. University, yichang 443002. china 2.School of Physics and Technology, Wuhan University, Wuhan 430072. china 3 Institute of Particle Physics, Central china Normal University, Wuhan 430070, china 1. College of Science China Three Gorges University Yichang 443002 China 2. School of Physics and Technology Wuhan University Wuhan 430072 China 3. Institute of Particle Physics Central China Normal University Wuhan 430070 China

The features of nuclear stopping power and multi-hadron production systematically are studied by making an analysis of rapidity distributions of pion and proton at AGS, SPS and RHIC in this work. It is found that nuclear stopping power increases linearly with project rapidity yp at AGS and SPS, but that is not liner at RHIC. It is argued that the average rapidity loss is saturated at central rapidity region at RHIC. For pion distribution, it is found that the phase space of pion distribution distributes uniformly in the longitudinal direction,and a linear relationship of L with log s is given at AGS and SPS. Non-uniform flow model may explain the features of the distribution at AGS and SPS, but may not ex- plain those of at RHIC.

关键词： non-uniform flow model average rapidity loss baryon number density nuclear stopping power

CIRCULAR CHROMATIC NUMBER AND MYCIELSKI GRAPHS

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Acta Mathematica Scientia 2006年第2期26卷 314-320页

作者：刘红美 College of Science three gorges University Yichang 443002China

For a general graph G, M（G） denotes its Mycielski graph. This article gives a number of new sufficient conditions for G to have the circular chromatic number xc（M（G）） equals to the chromatic number x（M（G））, ... 详细信息

关键词： Circular chromatic number Mycielski graphs chromatic number

Ecological hydrograph based on Schizothorax chongi habitat conservation in the dewatered river channel between Jinping cascaded dams

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Science china(Technological Sciences) 2011年第S1期54卷 54-63页

作者： LI RuoNan 1,CHEN QiuWen 1,2.& Duan Chen 1,3 1 Research Center for Eco-environmental Science,Chinese Academy of Sciences,Beijing 100085,china 2.china {2. gorges University,yichang 443002.china 3 Hydraulics Department,Changjiang River Scientific Research Institute,Wuhan 430010,china 1. Research Center for Eco-environmental Science Chinese Academy of Sciences Beijing 100085 China 2. china three {2. University Yichang 443002 China 3. Hydraulics Department Changjiang River Scientific Research Institute Wuhan 430010 China

Hydropower development changes the river hydrological regime,thereby altering river ecosystem *** important measure for reducing degradation of ecosystem is to determine ecological flow and implement it by reservoir *** paper described a method to calculate river ecological flow based on fish habitat conservation and applied it to Jinping River Bend of Yalong *** chongi was selected as target species,and the fish habitat model coupling with water environmental model was developed according to the relationship between fish and water environment ***,improved hydraulic habitat suitability index(IHHS) and habitat fragment index(HFI) varying with discharge were discussed in this *** area representing average annual flow was taken as a reference,and then ecological hydrographs under different habitat conservation levels were calculated considering season variation and life stages of *** to the natural condition,the model results indicated that the reservoir operation clearly influenced the habitat of the target *** was proposed to ensure flow releases to maintain 70%-90% habitat in section after joint while about 60% before joint.

关键词： river habitat habitat assessment ecological flow ecological hydrograph