Journal of Hydraulic Engineering
No.02 1999
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Journal of Hydraulic Engineering No.02 1999 |
The combination forecasting using artificial neural network based on wavelet transformed sequences
Li Xianbin,Ding Jing,Li Houqiang
(Sichun Union University)
Abstract A new combination forecasting method of hydrologic time series is introduced.The wavelet Coefficients in octaves are deduced from A Trous wavelet transform and the artificial neural network is used in multi-scale combination forecasting of these coefficients.Based on the formula reconstructed by using A Troustranform, the forecasted hydrologic time series are obtained.The effectiveness of this method is verified by an example.
Key words A Trous wavelet transform, artificial neural network, combination forecasting.
Stability study of slabs at the bottom of plunge pools downstream of high dams
Liu Peiqing
(Beijing University of Aeronautics and Astronautics)
Abstract The stability of bottom slabs of flat and curved floors for plunge pools downstream of high arch dams is investigated in this paper.The stability conditions of the slabs are deduced by analyzing the equilibrium of the fores acting on the slabs.The results can be applied to the design of plunge pools.
Key words plunge pool,slabs,stability conditions.
Numerical simulation of riverbed horizontal variation for the lower reaches of Yellow River
Huang Jinchi, Wan Zhaohui
(China Institute of Water Resources and Hydropower Research)
Abstract This paper gives a special treatment on the river bed adjustment mode,especially for the horizontal variation.According to the data from Yellow River,the horizontal variation of riverbed can be divided into two parts,i.e.erosion at the toe of a bank and collapse of bank.Based on the analysis on the equilibrium of the forces,a new method for simulating the horizontal variation of the riverbed is proposed.The validity of the method is verified by the observed data in 1977 referring to a typical high sediment laden flood which peak concentration reached 546kg/m3.
Key words Yellow River,lower reaches,horizontal variation,riverbe d,numerical simulation.
A computational model of shield tunnel for water conveyance
Zhang Qing, Zhuo Jiashou
(Hohai Univeristy)
Abstract Based on the theory of interface stress element for d iscontin uous media,a computational model of shield tunnel for water conveyance is estabi lished in this paper.In the model,the continuous condition of interface displacement is neglected and the effects of binder bolt for connecting the sectors of li ner tubes as well as the discontinuous deformation characteristics of various cracks are simulated.Theoretical analysis and practical computation results show that the proposed model is accurate and efficient.
Key words shield,tunnel for water conveyance,discontinuous mechan ics,computational model,engineering application.
A practical method for solving the optimal problems in complica ted engineering
Xiao Zhuanwen, Xu Riqing, Gong Xiaonan
(Zhejiang University)
Abstract A practical method by combining GA with ANN is used to solve the optimal problems in complicated engineering.The method used not only the nonlinear mapping,network reasoning and prediction of neural networks but also the global optimal characteristics of genetic algorithm.It can be widely used to solve various complicated engineering problems that target functions can't be expressed by apparent functions of decisive variables.
Key words genetic algorithm, artificial neural networks, global optimal, complicated engineering.
The experimental research on the shear behavior of partial steel fiber reinforced concrete beams
| Gao Danying |
| (Zhengzhuo University of Technology) |
| Zhao Jun |
| (Zhengzhou University) |
| Zhu Haitang, Zhang Qiming |
| (Zhengzhou University of Technology) |
Abstract Based on the experiment and analysis of reinforced concrete beams and partial steel fiber reinforced concrete beams,the effect of the thickness of fibrous tensi le zone,the volume fractions of steel fiber and the ratio of shear-span to effective-depth on shear behavior of partial steel fiber reinforced concrete beams are discussed.The model for calculation and corresponding formula are establishe d which is complied with those of the conventional reinforced concrete beams.
Key words partially reinforced, tensile zone, shear behavior.
Ni Hangen，Liu Hansheng
(Dalian University of Technology)
Abstract The charateristics of the radial contracted flow is analyzed and the expression of the surface slope of the flow is obtained. A new idea for design of slit-type buckets is proposed, that is to form the radial contracti on of the flow at the outlet. Accordingly, the design method isdrafted.
Key words radial contraction flow, slit-bucket, design, contraction , section.
Study on mathematical model for muddy water intermittent infiltration
Fei Liangjun,Wang Wenyan
(Xian University of Technology)
Abstract Three intermittent infiltration mathematical models for muddy water are proposed. The calculation precision of these models are verified by experiments in field.
Key words muddy water, surge flow irrigation, intermittent infiltration model, infiltration parameters.
The inverse function method for analyzing the data of one-dimension sand column dispersive test
Guo Jianqing,Qian Hui
(Xian College of Engineering Science)
Abstract Inverse function conversion was conducted for approximate analytical solution of semi-infinitive sand column during dispersive test under the condition of one dimensional steady flow and injection of tracer with constant concentration.The converted mathematical expression can be applied to analyze the data for determining the longitudinal dispersive coefficient of the test media.The method has better accuracy than the current method and can be applied to the case of fewer data.The computing procedure can be programmed and carried out with computer.
Key words dispersive test, inverse function method, dispersive coefficient.
Graphic theory applied to pipe-network hydraulic analysis
| Shi Ji |
| (Dagang Oilfield Group Co.Ltd.Design Institute) |
| Zhang Fengzhou |
| (Yellow River Administration of Henan Province) |
| Wei Yongyao |
| (Wuhan University of Hydraulic and Electric Engineering) |
Abstract By using Graphic theory, the calcualtion of the pipe-network becomes simple, convenient and credible. Moreover, pipe-network acces sories can be computed easily. In addition, the information of pipe-network can be input simply and quickly. It can be applied to hydraulic analysis of large pipe-network by using computer.
Key words pipe-network, hydraulic analysis, graphic theory.
Study on optimal operation of multi-reservoir system in an intensive agriculture district
Lei Xiaoyun
(Shi Hezi University)
Chen Huiyuan,Feng Shangyou
(Wuhan University of Hydraulic and Electric Engineering)
Abstract Based on goal programming principle of large scale system decomposition coordination technique and the simulation technique, the nonbad solution of subsystem is deduced. The large scale system coordination simulation and subsystem simulation models are developed for multi-reservoir system. The method for multireservoir realtime operation system is studied and the program is developed.
Key words multireservoir, goal programming, simulation model, operation scheme.
Horizontal 2D flowsediment mathematical modeling for river crossing engineering
| Sun Dongpo |
| (North China Institute of Water Conservancy and Hydroelectric Power) |
Peng Wenqi |
(China Institute of Water Resources and Hydropower Research) |
Liu Peibin |
| (North China Institute of Water Conservancy and Hydroelectric Power) |
Abstract A depth averaged mathematical model is applied to simulate the flood flow and the deformation of river bed for a crossing engineering is SouthtoNorth Water Transfer Project of China. A procedure to treat moving boundary is adopted in this model. The model is calibrated by the data of typical flood flow.
Key words crossing engineering, river modeling, boundary tracking, local scour.
Study on the influence of hydraulic friction to transient flow
Yang Jianshe
(North China Institute of Water Conservancy and Hydroelectric Power)
Abstract Based on the simulation computation and theoretical analysis, this paper demonstrates the rises of water hammer pressure in prime pipe, analyzes the influence o f hydraulic friction to transient flow. An application of relative value of hydraulic friction per unit pipe length is discussed, which indicates the influence of hydraulic friction to transient flow. A practical example of the influence of hydraulic friction in penstock to transient flow of a hydropower station is given.
Key words transient flow, hydraulic friction, influence, analysis.
The influence of the soil and water conservation on the surface runoff in the watersheds in the gully plateau region of Loess Plateau
Mu Xingmin,Wang Wenlong,Xu Xuexuan
(Soil and Water Conservation Institute, Chinese Academy of Sciences and MWR)
Abstract In this paper the influence of the soil and water conservation on runoff quantity and its processes in typical small watersheds have been analyzed by using the parallel observation in two comparable watersheds in gully plateau region of Loess Plateau. The integral control of soil and water loss in the region can result in the decreases of flooding time, runoff modulus and runoff coefficient in the watershed. The yearly variation of the runoff modulus will be intensified due to the control of watershed.
Key words gully plateau region, Loess Plateau, soil and water conservation, watershed runoff.
Effects of the Initial Rotation Angle of Principal Stress on Dynamic Stability Analysis of Earth Dam
Fu Lei
(Beijing Municipal Institute of Hydraulic Engineering Planning,design and Research)
Wang Hongjing, Zhou Jinxing
(Tsinghua University)
Abstract In this paper a finite element program for dynamic analysis is developed, It can be used to analyze the dynamic stability of earth dam with consideration of the initial rotation angle. The differences between t he dynamic analysis with and without considering the initial rotation angle are compared through computation. The conclusion is that the dynamic failure zones obtained from computation with consideration of the effect of initial rotation angle is large than that without consideration of the effect.
Key words angle of principal stress rotation, earth dam, dynamic analysis.