Failure mechanism of bottom plate in stilling basin and
countermeasure for protection

LIU Pei-qing¹, LIU Xin-ai², LI Fu-tian³
(1.Beijing University of Aeronautics and Astronautics  2.Ministry of Water Resources  
3.China Institute of Water Resources and Hydropower Research)

Abstract: Based on the case study of stilling basin failure happened to several high dams, the important role of pressure fluctuation in causing failure is demonstrated. The basic characteristic and distribution of pressure fluctuation acting on the plate and formation of uplift force are theoretically analyzed to explain the effect of pressure fluctuation. Water stop, drainage system and anchoring are recommended as countermeasure to prevent the floor from uplifted¡£The design criterion of stilling basin floor referring to pressure fluctuationis proposed.

Key words: stilling basin; plate; design criterion

Abstract: The longitudinal stability index of estuary characterized by river bed degradation and aggradation intensity and the transversal stability index characterized by the ratio of river width to depth are proposed. By using these synthetic indexes the catastrophic model for describing the stability and evolution process of estuary is established based on the catastrophic theory. Thediscrimination of stability and the evolution mode can be deduced. The application to the analysis of the Qiantang River shows that the model is reasonable in explaining the evolution process and estimating the stability of the estuary.

Key words: estuary; stability; evolution; catastrophic model

Safety analysis of solute transport prediction in clay

WANG Jin-sheng¹, YANG Zhi-feng¹, WANG Li¹, LI Shu-shen²
(1.Beijing Normal University; 2.China Institute for Radiation Protection)

Abstract: The effect of immobile water volume in porous medium on radionuclide transport of radioactive waste disposal in saturated-unsaturated zone is studied. The experimental studies on physical property of loess and field tracer migration of tritium(³H) show that the average pore water velocity, which is the result of porosity or water content divided by flux of water, is smaller than actual average pore water velocity. The calculation result of tritium transported in unsaturated zone using convection-dispersion model demonstrates that the actual porous velocity is higher than that without considering the immobile volume by 1.39 times.

Key words:unsaturated zone; aquifer; convection-dispersion; prediction; radionuclide.

Genetic algorithm for operation optimization of multi objective decision
making in water resources system

FANG Hong yuan¹,DENG Yu mei², DONG Zeng-chuan³
(1.Yangzhou University;2.National Office of Flood Control andDrought Resistant;3.Hohai University)

Abstract: The application of genetic algorithm to multi objective decision making in water resources system is presented.According to the principle of genetic algorithm the solutuion is expressed in floating vector structure.The fitness is defined as the standardized distance between real objective point andideal goal point,based on the cordinating principle of multi objective decision making.The effectiveness of this method is demonstrated by an example.

Key words: multi objective decision making;water resources system;genetic algorithm

Analysis of water hammer in an uniform saturated soil column

QIN Yao dong¡¡,DU De jun¡¡,ZHANG Hai lin
(China Agriculture Univeristy,Beijing)

Abstract: The hysteresis phenomenon, that the variation of soil water output flux at the bottom of a vertical saturated column is lagged behind the step changing input from the top, is explained according to the water hammer theory. An output jumping to final flux is found when Dacy's law is applied to¡¡the analysis of soil water flow. A monotonic increase of output flux is obtained based on the capillary tube model. It is recommended that the statistical equation should be applied to the determination of output flux, since the elastic wave propagationvelocity is always unknown. Experimental result and theoretical analysis show that soil water carries information of soil system just as the transfer of dilute in soil,under the condition of step changing input. This indicates that water flux can be used as a signal for transfer function analysis.

Key words: transfer function; step changing input; water hammer; elastic wave

Study on irrigation benefit of rice in Pi Shi Hang irrigation district

WANG Jia xian
(Flood Control and Drough Relief of Auhui Provice)

Abstract£ºFor the purpose of economic analysis of water supply engineering so as to determine a rational water price, the Irrigation Experiment Station of Pi Shi Hang Irrigation District conducted an experiment on irrigation benefit of water supply for four types of climatic including years wetting, average, dry and extremely dry. Based on the statistics of rainfall and crop output ofthe years, combining with the experiment result, the irrigation benefits have been calculated by getting yearly benefit coefficient according to the rainfall frequency.

Pollutant effluent flowing from the four eastern outlets of PearlRiver
Delta into Lingdingyang sea

PANG Yong¹, LI Xue lin²
(1.Hohai University; 2.Water Resources Protection Bureau of Pearl
River Water Resources Commission)

Abstract£ºAn unsteady water quality hydrodynamic model for river network is applied to calculate the amount of pollutant effluent flowing from the four eastern outlets of Pearl River Delta into Lingdingyang sea. The hydrodynamicdata observed in dry, mean and flood periods are used to verify the validity ofthe model. Some variation trends of the pollutant amounts are obtained.

Key words£ºPearl River delta; water quality; hydrodynamic model; outlets; Lingdingyang sea

Representative element aggregation model for
jointed rock mass and prediction of elastic parameters

ª¤ª¤QIN Juan,GENG Ke qinª¬
(China Institute of Water Resources and Hydropower Research)

Abstract: The concept and model of representative element aggregation of jointed rock mass are proposed. The deformation behaviors of the rock mass arestudied by numerical simulation. The elastic model for jointed rock mass is established and the simulation method for predicting the macroscopic equivalent elastic parameters is introduced. The feasibility of this method is verified by engineering practice.

Key words:  jointed rock mass; representative element aggregation; elastic model; prediction of elastic parameters

The dynamic friction coefficient of materials for ice modeling

LI Zhi-jun, SHEN Zhao-wei, QU Yue-xia, LI Guang-wei
(Dalian University of Technology)

Abstract£ºThe properties of DUT-1 synthetic model ice(not formed by freezing) for hydraulic model test are introduced. The friction between the ice blocks in water with the same material, aluminum, painted wood and plasticare experimentally studied. The mean dynamic friction coefficient between the same material is 0.49,it is about the same as the natural ices and some model ices¡£In addition the measured dynamic friction coefficients between the model ice and aluminum, painted wood and plastic are 0.37¡¢0.57 and 0.38.The friction coefficient decreases with the increase of normal load and moving speed.

Study on water use of drip irrigated peach tree under the conditions of fully irrigated
and regulated deficit irrigation

LI Guang-yong¹, WANG Xiao-wei², HUANG Xiang-fa¹, ZHANG Xiao-ming²
(1.China Agriculture University 2Beijing Forest and Fruit Tree Research Institute)

Abstract£ºPeach trees planted on clay loam soil are divided into two districts with different irrigation conditions. In the first district, the trees arefully irrigated with water volume equivalent to 80% of evaporation in the totalgrowth period. Whereas, in the second district, the trees are irrigated according to regulated deficit irrigation principle with water volume equivalent to the sum of 20% of evaporation during fruit slow growth stage and 80% in the rest of growing period. It seems that the total yield of fruit does not decrease under the condition of regulated deficit irrigation but the water use is significantly reduced. The annual crop factors are 0.474 and 0.378 for full irrigation and regulated deficit irrigation respectively.

Optimal operation model for multi-reservoir in irrigation area and its application

MA Bin1, XIE Jian-cang, WANG Ni, ZHANG Yong-jin
(Xi'an University of Technology, Xi'an)

Abstract£ºAim at being water short of status in the Northwest irrigate section, based on the system theory,the mathematical model for optimal allocation of irrigation water supply from multiple sources is established.The application of this model to Baojixia irrigation system,Shanxi Province,is used as an example for illustration.According to the calculation,the scale of water supply project,amount of urban water supply and the optimal dispatch of multiple water resources are demonstrated.

Short term observation data forcasting based on Lyapunov exponent

CHEN Ji-guang
(Shandong University)

Abstract£ºThe chaos method is applied to analyze the observation data in time series.According to the observed deformation data and the Lyapunov exponent calculated,the forecasting can be made.The method for determining the delay time lag and embedding dimension in phase space reconstruction of chaotic time series is investigated.The effectiveness of the Lyapunov exponent method is demonstrated by an example.

Arbitrarily encrypted finite element gridding method for strength
cracking generation analysis of arch dam

ZHANG Xue-hu¹, ZHANG She-rong²,CHEN Zu-ping¹
(1.China Communications Planning and Design Institute for Water transportation;2Shougang Institute of Technology)

Abstract: Analytic relationship between occurrence of strength cracking and stress states is esablished and concepts of correlation element at surface, correlation element at line(arris) and correlation step are defined. The self-adapted 3-D stochastic method for arbitrarily encrypted finite element gridding under the restriction of correlation step euqal to 1 is developed. On this basis, the explicit description of strength cracking occurrence is resolved. An example is given to demonstrate the application of proposed method to cracking control and reasonable setup of induced joints.

Key words: attitude of strength cracking; finite element fission;self-adapted method;induced joint

Calculation method of flexural capacity of GFRP-reinforced concrete beam

GAO Dan-ying¹, B.Benmokrane²
(1.Zhengzhou University¡¡2University of Sherbrooke, Sherbrooke J1K 2R1, Canada)

Abstract: Based on the test results of 62 concrete beams reinforced with GFRP (glass fiber reinforced polymer) bars and steel bars, the objective of this paper is to analyze the influence of reinforcement ratio on cracking and ultimate moment capacity.It is found out that the effect of reinforcement ratio on caraking moment capacity is not significant, but the ultimate capacity of the GFRP over-reinforced concrete beams increases with the increase of the reinforcement ratio when the longitudinal reinforcement ratio ranging from balanced reinforcement ratio to limit reinforcement ratio. The corresponding formulas are recommended to calculate the craking moment and ultimate moment capacity of beams.

Key words: glass fiber reinforced polymer (GFRP); concrete; beam; cracking moment capacity; ultimate moment capacity

On tectonic stress in rock mass

ZHU Huan-chun, LI Hao
(Wuhan University)

Abstract: The distribution of tectonic stress in rock mass is studied based on the analysis of geological action and measured data. The horizontal stress ¦Ò is linearly varied with depth has ¦Ò=kh+T, where k and Tare coefficients. Tectonic stress can not only be described by the coefficient T, but also by k. On the other hand, even in flat area. In flat area, Treflects the possible subsequent geological action on the ground surface. Tectonic stress in uneven area can be effectively described by the difference between the maximum and minimum horizontal principle stress. In river valley area, the influence of surface geological action on in-situ rock stress is remarkable. However, the tectonic stress state can be identified by the original equivalent stress field before the formation of valley.

Key words:  tectonic stress; gravity stress; geological action; depth

Construction system simulation of large-scaleunderground structure group

ZHONG Deng-hua¹, ZHANG Wei-bo¹, ZHENG Jia-xiang²
(1.Tianjin University 2.Chengdu Hydroelectric Investigation Design Institute)

Abstract:   The integrated technology for construction system analysis of underground structure group is developed. It consists of cyclic operation network, network planning and optimizing, visual resource-oriental modeling and animation demonstration technique. The simulation is divided into 4 steps including simulation analysis of single underground tunnel or chamber, construction schedule analysis, construction simulation analysis of structure group and animation demonstration. The software, namely XLD, for calculation is developed and applied to the construction organization design of Xiluodu Hydropower Project.

Key words:   large-scale underground structure group; construction; system simulation; visual modeling; animation demonstration

Case study of a wind destroyed aqueduct

PAN Dang guang, LOU Meng lin, LI Yu chun
(Tongji University)

Abstract£ºA wind destroyed aqueduct is analyzed by using FEM to findout the cause of failure. The result shows that under the action of wind pressure the connection between the beam and supporting base becomes a plastic hinge forming the whole structure working as a movable mechanism and causing the failure of the aqueduct. On this basis, the measure for enhancing the resistance to wind of the aqueduct, including the increase of beam cross section and installation of diagonal braces, is recommended.