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

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,china three gorges university,yichang 443.02,china 2college of civil and hydropower engineering,china three gorges university,yichang 443.02,china 3Er’tan hydropower Development Company,Ltd.Chengdu 61000,china Key Laboratory of Geological Hazards on three gorges Reservoir Area Ministry of Education China Three Gorges University Yichang China college of civil and hydropower engineering China Three Gorges University Yichang China Er’ tan hydropower Development Company Ltd. Chengdu 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

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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 gorges university,yichang 443.02,china 2 college of hydropower engineering,Xi’an university of Technology,Xi’an 710048,china college of Hydraulic and Environmental engineering China Three Gorges University Yichang China college of hydropower engineering Xi’an University of Technology Xi’an 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

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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 443.02,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 college of civil & Hydroelectric engineering China Three Gorges University Yichang China School of Water Resources & hydropower engineering Wuhan University Wuhan China Institute of Earth Environment Chinese Academy of Sciences Xi’an 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

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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, china three gorges university, yichang 443.02, china 2 School of civil engineering, Wuhan university, Wuhan 430071, china 3 university of Sciences and Technologies of Lille, Lille 59655, France Key Laboratory of Geological Hazards on three gorges Reservoir Area Ministry of Education China Three Gorges University Yichang China School of civil engineering Wuhan University Wuhan China university of Sciences and Technologies of Lille Lille 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

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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 210098, china 2 china Yangtze River three gorges Project Development Corporation, yichang 443.02, china 3 china Institute of Water Resources and hydropower Research, Beijing 100044, china college of Water Conservancy and hydropower engineering Hohai University Nanjing China china Yangtze River three gorges Project Development Corporation Yichang China china Institute of Water Resources and hydropower Research Beijing 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

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Global analysis on slope stability and its engineering application

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Science china(Technological Sciences) 2009年第2期52卷 507-512页

作者： ZHENG Hong1,2 & ZHOU ChuangBing3 1 State Key Laboratory of Geomechanics and Geotechnical engineering, Wuhan 430071, china 2 china three gorges university, Key Laboratory of Geological Hazards on three gorges Reservoir Area, Ministry of Education, Yi Chang 443.02, china 3 School of civil engineering, Wuhan university, Wuhan 430072, china State Key Laboratory of Geomechanics and Geotechnical engineering Wuhan China china three gorges university Key Laboratory of Geological Hazards on Three Gorges Reservoir Area Ministry of Education Yi Chang China School of civil engineering Wuhan University Wuhan China

In hydraulic engineering, sometimes it is necessary to consider the stability of sliding bodies with lateral frictional boundaries. Neither the existing three dimensional limit equilibrium methods nor the commercial software products are able to treat such situations. The three dimensional factor of safety is accordingly underestimated; while the shearing strength based on the three dimensional back analysis is overestimated. In this study, the lateral boundaries are regarded as the part of the slip surface. Based on the expression of the normal pressure on the slip surface and the patch interpolation, a rigorous solution for the three dimensional limit equilibrium analysis is realized. Meanwhile, the proposed procedure is applied to the stability analysis of the slope with a cable platform on the right bank in Da Gang Shan hydraulic project under construction.

关键词： slope stability the limit equilibrium methods three dimensional problems

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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 gorges Project Corporation, yichang 443.02, china 2 State Key Laboratory of Hydroscience and engineering, Tsinghua university, Beijing 100084, china china three gorges Project Corporation Yichang China State Key Laboratory of Hydroscience and engineering Tsinghua University Beijing 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 2004 to 2006 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 2004―2006 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 20 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 3200 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

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Multi-dimensional project management models for mega-construction companies and their applications

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Science china(Technological Sciences) 2011年第S1期54卷 118-124页

作者： LIN ZhengHang 1,2,QIANG MaoShan 1,2,TANG WenZhe 1,2,FAN QiXiang 3 &LIU Qiang 4 1 Institute of Project Management and Construction Technology,Tsinghua university,Beijing 100084,china 2 State Key Laboratory of Hydraulic and engineering,Tsinghua university,Beijing 100084,china 3 china three gorges Corporation,yichang 443.02,china 4 School of Software,Tsinghua university,Beijing 100084,china Institute of Project Management and Construction Technology Tsinghua University Beijing China State Key Laboratory of Hydraulic and engineering Tsinghua University Beijing China china three gorges Corporation Yichang China School of Software Tsinghua University Beijing China

china is undertaking an increasing number of mega-infrastructure projects along with its rapid economic *** participants in these projects,understand how to adapt the proper and efficient management strategies is *** this paper,we propose three distinct models for companies under various background and management requirements,based on sophisticated data analysis and model ***,we successfully committed these models with hydropower development projects and achieved a great progress in enhancing management efficiency.

关键词： project management models mega-construction companies applications hydropower development companies

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Decision Support System for Emergency Response of Geological Hazards in three gorges Reservoir Area

Decision Support System for Emergency Response of Geological...

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2010 Second International Seminar On Business and Information Management (ISBIM 2010)

作者： Haifeng HUANG college of civil engineering and Architecture china three gorges university yichang china Shimei WANG college of civil engineering and Architecture china three gorges university yichang china

china three gorges reservoir area（TGRA） has always been severe geological hazards,and it gets worse when reservoir water level rises greatly with the construction of dam,emergency response of geo-hazards is becoming a frequent and important *** guarantee the order and high efficacy,it is necessary to establish decision support system to assist the decision makers to work out perfect emergency response *** to years of experience in TGRA,on the basis of summarizing emergency response framework that included emergency survey,risk assessment and emergency decision-making,a decision support system for emergency response of geo-hazards in TGRA,which consisted of database,model base,knowledge base,case base and inference machine was established,and three decision-making processes included emergency preplan decision-making,emergency plan decision-making and emergency measures decision-making were *** application effect indicated the DSS system had good practicability because it could not only meet the multi-level and multi-task requirement of geo-hazards emergency response decision-making,but also tally with the practical scenarios.

关键词： decision support system emergency response geological hazards three gorges reservoir area

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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 three gorges university,yichang 443.02,china 3 Hydraulics Department,Changjiang River Scientific Research Institute,Wuhan 430010,china Research Center for Eco-environmental Science Chinese Academy of Sciences Beijing China china three gorges university Yichang China Hydraulics Department Changjiang River Scientific Research Institute Wuhan 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

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