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Establishing time-dependent model of deformation modulus caused by bedrock excavation rebound by inverse analysis method

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Science china(Technological Sciences) 2008年第S2期51卷 1-7页

作者： WU ZhongRu1,2,GU YanChang1,3,GU ChongShi1,2,GUO HaiQing1 & SU HuaiZhi1,2 1 Hohai University,Nanjing 210098,china 2 National Engineering research Center of water resources Efficient Utilization and Engineering Safety,Nanjing 210098,china 3 Nanjing Hydraulic research institute,Nanjing 210029,china Hohai University Nanjing China National Engineering research Center of water resources Efficient Utilization and Engineering Safety Nanjing China Nanjing Hydraulic research institute Nanjing China

Rock rebound relaxation deformation,or even rock burst,caused by the excavation of dam base and abutment or high rock slope affects their stability and results in the fall of mechanical properties of the *** an inverse analysis method was proposed in this paper to establish the time-dependent model of deformation modulus caused by excavation *** basic principle is based on the combination of observed data of the excavation rebound deformation of dam abutment or rock slope,and the calculated rebound deformation by FEM under ground stress at the corresponding time in the excavation *** norm of the residuals of observed data and calculated data are taken as the objective ***,the time-dependent model of bedrock deformation modulus can be *** method displays its significance in the design of excavation,construction and operation management of dam base and high slope.

关键词： dam base rebound deformation modulus inverse analysis method time-dependent model Xiaowan hydropower Station

EXPERIMENTAL STUDY OF LANDSLIDE DAM-BREAK FLOOD OVER ERODIBLE BED IN OPEN CHANNELS

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Journal of Hydrodynamics 2009年第1期21卷 124-130页

作者： YAN Jun CAO Zhi-xian LIU Huai-han CHEN Li State Key Laboratory of water resources and hydropower Engineering Science Wuhan University Wuhan 430072China Changjiang waterway institute of Planning Design and Research Wuhan 430011 China

Large-scale landslide dams may block the river flow and cause inundation upstream, and subsequently fail and result in severe flooding and damage in the downstream. The need for enhanced understanding of the inundation and flooding is evident. This article presents an experimental study of the inundation and landslide dam-break flooding over erodible bed in open channels. A set of automatic water-level probes is deployed to record the highly transient stage, and the post-flooding channel bed elevation is measured. New experimental data resources are provided for understanding the processes of landslide-induced flooding and for testing mathematical rivers models.

关键词： landslide dam dam-break sediment transport

Relationship between Environmental Pollution of Coal Mine and Spectral Characteristics of Nearby Plants

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Journal of University of Science and Technology Beijing 2001年第1期8卷 10-14页

作者： Liqing Lei institute of Geographic Sciences and Natural resources research, Chinese Academy of Sciences, Beijing 100101, china Inst. of Geogr. Sci./Nat. Rsrc. Res. Chinese Academy of Sciences Beijing 100101 China

Remote sensing technology, as the most advanced method for collecting data, along with the common ways often used in the past on research of environmental science, was integrated to study the relationship between environmental pollution of coal mine and spectral characteristics of nearby plants. With compositive index and mean reflectivity at near infrared, a regression equation was established, and a conclusion was made that spectral reflectivity can be used to distinguish regions with different pollution degree. Through testing with real status of the research region, it is verified that this kind of integration and conclusion not only are helpful for human being in controlling the movement law of pollutants and the corresponding change of coal mine environmental quality but also bring a new way for the research of environment problems of coal mine.

关键词： remote sensing spectral characteristics reflectivity pollution index compositive index atmospheric pollution

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 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

A 2-D HYDRODYNAMIC MODEL FOR THE RIVER,LAKE AND NETWORK SYSTEM IN THE JINGJIANG REACH ON THE UNSTRUCTURED QUADRANGLES

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Journal of Hydrodynamics 2010年第3期22卷 419-429页

作者： ZHANG Xi-bing HU De-chao WANG Min State Key Laboratory of water resources and hydropower Engineering Science Wuhan University Wuhan430072 China Yangtze River Scientific research institute Wuhan 430010 China State Key Laboratory of Hydroscience and Engineering Tsinghua University Beijing 100084 China

The main river, the Dongting Lake and river networks in the Jingjiang reach of the Yangtze River constitute a complex water system, for which a full 2-D hydrodynamic model is established instead of the traditional 1-D or compound models for simulation of such complex systems, based on the latest developments of computer technologies and numerical methods. To better handle irregular boundaries and keep the computation cost well in a reasonable limit, unstructured grids of moderate scale are used. In addition, a dynamic boundary tracking method is proposed to simulate variable flow domains at different floods, especially, when the moderate scale gird can not describe flows in narrow river-network channels at low water levels. The t9 semi-implicit method and the Eulerian-Lagrangian Method （ELM） are adopted, which make the model unconditionally stable with respect to the gravity wave speed and Courant number restrictions. Properties and efficiency of the model are discussed, and it is concluded that the new model is robust and efficient enough for the simulation of a big, complex water system. Validation tests show that the simulation results agree well with field data. It takes about 0.96 h to complete the computation of a 76 d flood, which indicates that the model is efficient enough for engineering applications.

关键词： 2-D numerical model river network unstructured grid semi-implicit Eulerian-Lagrangian Method (ELM) boundarytracking

Key technical problems of extra-high concrete faced rock-fill dam

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Science china(Technological Sciences) 2007年第Z1期50卷 20-33页

作者： MA HongQi1? & CAO KeMing2 1Yunnan Huaneng Lancang River hydropower Co., Ltd., Kunming 650011, china 2East china Investigation, Design & research institute, Hangzhou 310014, china Yunnan Huaneng Lancang River hydropower Co. Ltd. Kunming China East china Investigation Design & Research Institute Hangzhou China

This paper summarizes the main technical points related to 100 m-height-scale concrete faced rock-fill dams and analyzes the main problems and their causes occurring during construction of 200 m-height-scale concrete faced rock-fill dams. This paper has raised the key technical problems which need to study for construction of 300 m-height-scale concrete faced rock-fill dams based on the main experiences on the extra-high concrete faced rock-fill dams built after the year of 2000.

关键词： concrete faced rock-fill dam extra-high dam key technology

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

THE EARTHQUAKE FREE FIELD INPUT MODEL OF ARCH DAMS WITH CONTRACTION JOINTS AND ITS ENGINEERING APPLICATION

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THE EARTHQUAKE FREE FIELD INPUT MODEL OF ARCH DAMS WITH CONT...

CHARACTERISTICS OF FLOW RESISTANCE IN OPEN CHANNELS WITH NON-SUBMERGED RIGID VEGETATION

水电2006国际研讨会

作者： Zhang Boyan1 Chen Houqun2 Li Deyu3 1 china institute of water resources and hydropower research Beijing 100044 china 2.china institute of water resources and hydropower research Beijing 100044 china 3 china institute of water resources and hydropower research Beijing 100044 china

The earthquake free field input model of arch dams with vertical contraction joints is introduced, in which the spring-viscous boundaries are employed to absorb out-spread waves, dynamic interaction between the dam and the water retained in the reservoir as well as the deformable foundation rock is considered, and Lagrange Discontinuous Deformation Analysis （LDDA） is implemented to model the opening and closing of vertical contraction joints in arch dams. The free field displacements, velocities and stresses of the stratum foundation are translated into boundary loads at finite element boundaries to solve the system responses. And a new high efficient iterative algorithm for dynamic contact forces is presented, in which the relax factor is chosen by physical character not mathematic theory. As the practical engineering application, the dynamic analyses for the proposed Dagangshan Arch Dam and its foundation system is carried out. The analysis results indicate significant reduction in dynamic stress because of infinite rock foundation radiation damping, and show the release of arch tension stresses and subsequent redistribution of forces due to the opening of the contraction joints. For the monolithic dam, when considered the infinite rock foundation radiation damping, dynamic arch stresses decrease by 42%-to-52%, dynamic cantilever stresses decrease by 53%-to-61%.

关键词： Arch Dam Free Field Earthquake Input Model Spring-viscous Boundary

来源： cnki会议评论

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Journal of Hydrodynamics 2008年第2期20卷 239-245页

作者： WU Fu-sheng Nanjing Hydraulic research institute Nanjing 210029 China State Key Laboratory of Hydrology-water resources and Hydraulic Engineering Nanjing 210029 China

The flow resistance factors of non-submerged rigid vegetation in open channels were analyzed. The formulas of drag coefficient CD and equivalent Manning＇s roughness coefficient na were derived by analyzing the force of the flow of non-submerged rigid vegetation in open channel. The flow characteristics and mechanism of non-submerged rigid vegetation in open channel were studied through flume experiments.

关键词： characteristics of flow resistance non-submerged rigid vegetation drag coefficient equivalent Manning's roughness coefficient