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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,China three gorges University,yichang 443.02.China 2College of Civil and Hydropower Engineering,China three gorges University,yichang 443.02.China 3.r’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

Minimum Exact Cover Problem of Group Key Distribution

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Wuhan University Journal of Natural Sciences 2009年第2期14卷 137-142页

作者： FU Xiong1,2, XU Shouzhi3.1. School of Law ,Wuhan University, Wuhan 43.072, Hubei, China 2. Department of Technology, Guangzhou Luogang District People’s Court, Guangzhou 51073., Guangdong, China 3. College of Electronic Engineering and Information Technology, China three gorges University, yichang {3. Hubei, China School of Law Wuhan University Wuhan China Department of Technology Guangzhou Luogang District People’s Court Guangzhou China College of Electronic Engineering and Information Technology China Three Gorges University Yichang China

Secure group communications are restrained by the number of the group size, number of changes and their distribution, all existing works do not meet the commands of applications with large group size and high dynamic members. In this paper, minimum exact cover problem for group key distribution （GMECP） is presented, and a heuristic solution is testified. Then an algorithm of batch rekeying with renewing cost tending to zero is illustrated, which can process any large number of change requests with best security guaranteed. Efficiency analysis and simulation test show that the achievement can improve the efficiency of any tree-based group key management.

关键词： minimum exact cover problem group key distribution secure multicast group key management

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, {3. 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

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 43.071, 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

Deformation in the three gorges Reservoir after the first impoundment determined by GPS measurements

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Progress in Natural Science:Materials International 2005年第6期15卷 515-522页

作者： DU Ruilin 1,2 , QIAO Xuejun 1,2 *, WANG Qi 1,2 , XING Canfei 1,2 and YOU Xinzhao 1,3.(1. Institute of Seismology, CEA, Wuhan 43.071, China 2. Laboratory of Crustal Movement and Earth Observation, Wuhan 43.071, China 3. Center for Analysis and Prediction, CEA, Beijing 10003., China) Institute of Seismology CEA Wuhan 430071 China Laboratory of Crustal Movement and Earth Observation Wuhan 430071 China Center for Analysis and Prediction CEA Beijing 100036 China

A 6-year long GPS observation (1998—2003. indicates that crustal deformation in the three gorges area is less active at a marginally measurable rate of 0—5 mm/a relative to stable South China block. However, the impounding water in June 2003.has induced transient displacement at the three gorges dam and the emerging reservoir. GPS measurements after the first stage of water filling of the reservoir demonstrate that vertical subsidence close by Yangtze River is about 10—40 mm, and the horizontal displacement is less than 5—10 mm. The maximum subsidence induced by the impoundment is located in the segment of the reservoir from Maoping to Xiangxi. The water loading-induced deformation diminishes rapidly with the distance from banks of the reservoir. The overall pattern of transient deformation is consistent with the simulation result of Farrell, and is attributed to the elastic response of upper lithosphere crust to overlying water reservoir.

关键词： three gorges GPS impoundment deformation.

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 gorges University, yichang {3. China 2 School of Physics and Technology, Wuhan University, Wuhan 43.072, China 3.Institute of Particle Physics, Central China Normal University, Wuhan 43.070, China College of Science China Three Gorges University Yichang China School of Physics and Technology Wuhan University Wuhan China Institute of Particle Physics Central China Normal University Wuhan 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

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 {3.China 3.Hydraulics Department,Changjiang River Scientific Research Institute,Wuhan 43.010,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

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 43.071, 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 43.072, 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

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,{3. 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