The 3-D stability analysis for arch dam abutment

CHEN Zu-yu, WANG Xiao-gang, WANG Yu-jie, WANG Jian, LU Feng
China Institute of Water Resources and Hydropower Research

Abstract: This paper describes a 3-D slope stability analysis method based on the upper-bound theory of plasticity. The failure mass is divided intoa number of prism with inclined interfaces. The plastic deformation velocity field can be determined based on the Mohr-coulomb associated flow lay. The factorof safety is obtained by the energy-work balance equation. The critical failure mode is obtained using the method of optimization. This method is applied to calculate the safety factor of the arch dam abutment in Xiaowan Project.

Key words: arch dam; abutment; slope; stability; the upper-bound analysis.

Study on evapotranspiration of winter wheat using SPAC model

MAO Xiao-min, SHANG Song-hao, LEI Zhi-dong, YANG Shi-xiu1
Tsinghua University

Abstract: Based on the simulation results of water and heat transfer in winter wheat field with soil-plant-atmosphere continuum(SPAC) model, the empirical formula for estimating crop evapotranspiration from the reference evapotranspiration and soil water storage between soil surface to 1m below is established. The empirical formula and SPAC model simulation are in good agreement under different irrigation treatments and different groundwater depths in winter wheatgrowing period from greening to mature.

Key words: SPAC model; evapotranspiration; crop coefficient; soil water supply coefficient.

Quantitative analysis of cracking due to over stress in arch dams

CHEN Zu-ping
(1.Shougang University)

Abstract: The advancement of study on cracking in arch dam is summarized. The flow diagrams for random tracking of cracking in arch dam based on load distribution-stiffness method and linear or nonlinear 3-D finite element methods are presented. The flow diagram for crakcing attitude tracking and for quantitative analysis of cracking at specific locations are established according to the 3-D linear FEM. Problems in quantitative analysis of cracking pending for solution are discussed.

Key words: arch dam; cracking due to over stress; quantitative description; cracking attitude; probability

The equivalent dynamic shear modulus and equivalent
damping ratio of rockfill material for dam

ª¤ª¤KONG Xian jing, LOU Shulian, ZOU De gao, JIA Ge xu, HAN Guo-cheng
(Dalian University of Technology)

Abstract: The equivalent dynamic shear modulus and equivalent damping ratio of rockfill material in several hydro projects are experimentally investigated using large scale triaxial test apparatus.On the basis of experimental results and elastic waves measured from 8 dams both in China and abroad,a formula for evaluate the maximum dynamic equivalent shear modulus and a reference range of the modulus are proposed.In this range the normalized dynamic equivalent shear modulus and dynamic damping ratio are related to the amplitude of dynamic shear strain.The dynamic parameters of rockfill material can be estimated according to the proposed formula and the reference range,in case the test data is not enough.

Key words: rockfill material; dynamic shear modulus; damping ratio;field test; shear wave

Numerical simulation for the coupled problem of temperature
and seepage fields in dams located in cold area

ª¤ª¤LAI Yuan ming^1,2, LIU Song yu¹, DENG Xue jun¹, J.M.Konrad³
(1.Southeast University,Nanjing; 2.Cold and Arid Regions Environmental and Eningeering Research Institute,ACS;
3.Laval University,Sainte Foy,QC,G1K 7P4,Canada)

Abstract: A mathematical model and the governing differential equations of the coupled problem of temperature and seepage fields with phase change arederived on the basis of heat transfer and seepage theory.The finite element formulae of this problem are obtained from Galerkin's method.An illustrative example of the temperature field in a dam located in cold region is provided.It shows that the effect of seepage field on temperature field is remarkable.Consequently,this factor must be considered in the design of dams in cold area.

Key words: dam;cold region;temperature field;seepage field;coupled modeling;numerical simulation

The application of threshold procedure in design of river and coastal engineering

ª¤ª¤QIU Xue yan ,WANG Chao ,QIN Chong ren
(Tianjin University)

Abstract: In view of the thresholds of current sampling method for probability analysis of design parameters including wind,wave and tide are determined empirically,a new procedure for determining the threshold based on mathematical theory according to the characteristics of peak over threshold is proposed.A series of figure such as mean residual life diagram and diagnostic check diagramfor calculation are provided.

Key words: threshold;peak over threshold;extreme value distribution;probability analysis

Two dimensional numerical simulation of solute transport in Liulin spring local

areaWU Ji-chun¹, XUE Yu-qun¹, HUANG Hai¹, ZHANG Zheng-zhi²
(1.Nanjing University; 2.Reconnaisance and Design Institute for Power)

Abstract: A 2-D local regional mathematical model for miscible solutetransport is presented. In the model the fluid density variation due to solution concentration change and the head distribution variation resulted from the fluid density change are considered. The model is applied to describe the transportbehavior of Clª¬- in the groundwater of Luilin spring area. The simulated values agree well with the field data. Thus, the model is used to forecast the compact on regional distribution of groundwater level and chloride concentration when Luilin spring is used as a water supply center.

Key words: fracture; solute transport; mathematical model; numerical simulationª¤

An improved method for calculating unconfined seepage
with changing element conductivity matrix

Key words: finite element; unconfined seepage; free surface; conductivity matrix; permeability coefficient

The characteristics of crack and deflection and its calculating method
of concrete beam reinforced with glass fiber polymer bars

GAO Dan-ying¹, ZHAO Junª¬1, B.Benmokrane²
(1.Zhengzhou University, China; 2.University of Sherbrooke,J1K 2R1,Canada)

Abstract: The characteristics of concrete beams reinforced with glass fiber polymer bars were investigated experimentally.Based on these test results the effects of bar's type and reinforcement ratio on the crack spacing,crack width as well as the deflection of the beam are studied in detail.A method for calculating the crack width and deflection of this kind of beam is suggested.

Key words: glass fiber reinforced polymerbar; concrete; beam; crack width; deflection

Discussion on policies and funding scheme for resettlement
from flood retention areas to township

WANG Dong-sheng1,LIU Shukun1
(China Institute of Water Resources and Hydropower Research)

Abstract: Flood retention areas play important role in flood control of China.However,the contradiction between development and flood control is getting intensified due to the rapid growing of population.Based on the analysis of necessity and feasibility of resettlement from flood areas to township,the problems may occur to the assessment of resettlement capacity are investigated.The policies for encouraging the people to move are recommended and the funding scheme for supporting the resettlement is suggested.

Key words: flood retention area; resettlement policy; town development; funding

On the eveluation and prediction of urban flood economic loss

FENG Ping,CUI Guang-tao,ZHONG Yun
(Tianjin University)

Abstract: The synthetic effects of the suffered body due to disaster,factors leading to disaster and environment forming disaster on urban flood disaster are investigated¡£The changing trend of urban flood disaster mode and the effect of urbanization on characteristics of flood disaster are summarized.A model for evaluation and prediction of direct economic loss is established.The model is applied to the evaluation and prediction of the flood disaster loss happened to the littoral region of Tianjin city.

Key words: urban flood disaster; economic loss; disaster mode; parameter statistic

Grain size variation of suspended sediment due to soil conservat
ionin the middle reach of Yellow River

HAN Peng¹, NI Jin ren²
(1.Tsinghua University¡¡;2.Peking University)

Abstract£ºGrain size variation of suspended sediment before and aftersoil conservation at some hydrologic stations and in the whole study area are analyzed with statistical method and Wilcoxon signed rank test method respectively. The statistical result of hydrologic stations shows that the sediment becomesmore fine when the soil conservation was implemented and reaches very high level. The long term variation of the grain size within the catchment also reveals atrend of becoming more fine, Which is resulted from the effect of large scaleactivity of soil conservation. Furthermore, qualitative analysis of the geomorphologic effect on grain size is investigated.

Key words£ºwater and soil conservation; middle reach of Yellow River;suspended sediment; composition statistical method

The geochemical method for studying hydraulic relationships
among porous medium reservoirs

WANG Xin-yi^1,2ªª, HAN Peng-fei³, LIAO Zi-sheng¹, LIN Xue-yu¹
(1.Beijing Normal University; 2.Jiaozuo Institute of Technology;3.Water Conservation Office)

Abstract: According to the differences of geological and hydrogeological characteristics, the geothermal system of Kaifeng city in the depth of 300 to1600m is divided into six reservoirs. The difference of hydrochemical characteristics between the geothermal systems in the depth less than 1300m and in the depth from 1300m to 1600m is analyzed. By using the radioactive isotope ¹⁴C, the ages and circulating rates are calculated. The source of geothermal water is found using steady isotopic method. According to the chemical equilibrium theory of mineral-fluid, the equilibrium state and equilibrium temperature isstudied.

Key words: porous geothermal system; reservoirs; water chemical element; isotope method;mineral-fluid, chemical equilibrium simulation

The large eddy simulation method for computation of 3-D
unsteady periodic turbulent flow in draft tube

YANG Jian-ming, LIU Wen-jun, WU Yu-lin
(Tsinghua University)

Abstract: The two-equation model for large eddy simulation is appliedto calculate the unsteady periodic turbulent flow in a draft tube. A multiple-block structure of grid for calculation of flow in complicated zone is proposed.The main characterstics of the eddy and pressure fluctuation are found.

Key words: large eddy simulation; two-equation model; unsteady periodic turbulent flow; draft tube

Asymmetric slit buckets with function of changing flow direction

NI Han-gen¹, LIU Han-sheng², LIANG Chuan³
(1.Dalian University of Technology; 2.Northwest Hydraulic Research Institute; 3.Sichuan University)

Abstract: The hydraulic characteristics of asymmetric slit bucket having linear side walls with function of changing flow direction is studied. It is found that the deflection angle of the out going flow is equal to the differenceof the deflection angles of side walls and the flow depth and Froude number at the exit of the bucket will not change if the sum of the deflection angles keepsthe same. The design principle of this kind of bucket is proposed. The impact force of the nappe acting on downstream riverbed measured in model test shows theasymmetric bucket is better than the symmetric one.

The application of preferred plane theory to geotechnical engineering practice

ª¤ª¤JIAN Jian ping¹, ZHANG Yang song²£¬LUO Guo yu¹, YAN Chenag hong¹, WANG Ming-wu³
(1.Nanjing Universty;2.Nanjing University of Scienceand Technology;3.Hefei University of Technology)

Abstract: The development of preferred plane theory and its application to geotechnical engineering practice is summarized.This theory is effective insolving geotechnical problems including regional stability,mechanical parameters on preferred plane,rock mass quality,foundation deformation as well as the reinforcement of geotechnical engineering.The application of preferred plane theoryto analyze the stability of Runyang Hinghway Bridge on Yangtze River is introduced.

Key words: preferred plane theory;regional stability;mechanical parameters;rock mass quality;foundation deformation;reinforcement