Application of ANN method to real-time operation of drainage sy stem in plain polder region

ZHOU Zuhao¹, GUO Zonglou²
(1Wuhan University of Hydraulic and Electric Engineering, Wuhan 430072 ,
China;2Zhejiang University, Hangzhou 310029, China)

Abstract: This paper presents a real\|time optimum operation model est ablished for drainage system in plain polder area. The optimum part of this mode l is an NLP\|NLP model. For solving the optimal model, an ANN optimum algorithm, which can accelerate the convergence of the calculation, is applied. The model and the algorithm have been successfully used to the operation of drainage syste m in Sihu area, China.

Key words:drainage system; plain polder region; real\|time opera tion; ANN optimum algorithm

The application of Co-Universal Kriging method for estimation of groundwater table

CHEN Jianjun, GUO Qiaoyu, WANG Hongqi, WANG Jinsheng
(1Institute of Environmental Science, Beijing Normal University, Beijin g 100875, China)

Abstract:The principle of Co-Universal Kriging method for groundwate r table estimation, proposed by the authors, is presented in this paper. In this method, the elevat ion of the ground surface at the node of calculation is adopted as another co|r egionalized variable. A case study is used to demonstrate the acquistition me tho d of experimental variogram. The comparison of the result derived from Universal Kriging method and that from Co-Universal Kriging method shows that the later can provide with more precise estimation of the water table.

Key words:groundwater; water table estimation; Co-Universal Kri ging method; variogram; coregionalized variable

Hydraulic jumps in rectangular conduit with circular uppe r wall and horseshoe tunnel

MA Jiming¹, XIE Shengzong², LIANG Yuanbo1
(1Tsinghua University, Beijing 100084,China;2China Institute of
Water Resources and Hydropower Research, Beijing 100038,C hina)

Abstract:In this paper, the hydraulic jumps in rectangular conduit wi th circular upper wall and horse tunnel, which are very often used in water proj ects, are concerned based on momentum equation. Formulas for calculating the con jugate depths of hydraulic jump are deduced. The graphics for discrimination of critical depth are provided.

Key words:hydraulic jump; conjugate depths; critical depth; rectangul ar conduit; horseshoe tunnel

Probability analysis of nonlinear cracking process of arch dam

CHEN Zuping
(Shougang Institute of Technology, Beijing 100041,China)

Abstract:The stress analysis on arch dam and its rock foundation is c arried out according to the deformation theory. The nonlinear elasticity constit utive model is adopted. Several failure criterions and different performance fun ctions of concrete and rock are used according to corresponding stress state. Th e analysis of cracking process is based on the analysis on the reliability index field according to the 3-D stochastic finite element method. The cracking traj ectory can be found out from reliability index field. The assembly of the condit ional probability of the cracking trajectory is the probability vector of the cr acking trajectory. An example is given to demonstrate the analysis method.

Key words:arch dam; cracking trajectory; nonlinear analysis; pro bability vector; implicated failure element

Discussion on simulation of transient in air cushion surge chamber

WU Shiqiang, HU Qilie
(1Nanjing Hydraulic Research Institute, Jiangsu Nanjing 210029, China)

Abstract:The comparison of results from mathematical model and physic al model in vacuum tank for simulation of transient in air cushion surge chamber shows that the similarity laws of various quantities in model test may have inf luences on the dissimilarity of test results. The air concentration of water, sc ale effect, state transformation of air in chamber as well as the test condition s are the major factor affecting the reliability of test results. For this reaso n, the correction of model test result must be made.

Key words:air cushion surge chamber; numerical modeling; water h ammer pressure; model test in vacuum tank

Study on factors affecting the permeability of compacted soft ro ck

WEN Yanfeng, BIAN Jinghong, CAI Hong
(1China Institute of Water Resources and Hydropower Research, Beijing 100044£¬China)

Abstract:In this paper, the permeability characteristics of two kind s of sandy shale soft rock under the conditions of different compaction styly, c ontent of fine sand (d<5mm) and content of water are experimentally studied. Fur thermore, the permeability of compacted soil under different vertical pressure i s also determined. The results help to clarify how the permeability influenced b y compaction style, load condition and other factors.ª¤

Key words:soft rock; permeability; sampling; vertical load

The mesh densification method for 3-D FEM and its application

QIANG Tianchi£¬KOU Xiaodong,ZHOU Weiyuan
(1Tsinghua University, Beijing 100084£¬China)

Abstract:On the basis of the minimum potential energy theory, the co arse mesh and fine mesh of 3-D FEM are coupled by interface elements to solve t he problem of the displacement consistency between meshes with different densiti es. The problem of local densification in FEM is simplified and the contradictio n between calculation accuracy and efficiency is also coordinated. The validity of this proposed method is verified by the comparisons of calculated results wit h theoretical solution and the result by means of ordinary FEM.

Key words:3-D FEM; displacement consistency; mesh densificatio n; theory of minimum potential energy

3-D dynamic effective stress analysis on the aseismic stability of fly ash dam

ZHOU Jian£¬DONG Peng£¬QI Peijiang
(1Tongji University, Shanghai 200092£¬China)

Abstract:In this paper, the stability of fly ash under 8 degree earthquake is studied by using 3-D dynamic effective stress analysis method. In the analysis, the 3-D c haracteristic of the dam and the influence of vibrating pore water pressure on the material shear modulus are taken into account. The stability situation and m ost dangerous section of the dam during earthquake in different stages of constr uction are derived.

Key words:fly ash; seismic analysis; 3-D dynamic effective stre ss analysis method; dynamic stability; FEM

Shear wedge beam method of seismic response analysis for concrete faced rockfill dams(CFRDs)

KONG Xianjing, LIU Jun£¬ HAN Goucheng, NI Hangen
(1Dalian University of Technology, Liaoning Dalian 116024,China)

Abstract:In this paper, formulas for computing natural frequencies an d modes of CFRDs are derived based on the additional mass and stiffness method a ccording to shear wedge beam theory. The influences of concrete-face to natural frequencies and modes are discussed. Furthermore, the seismic responses of CFRD s are calculated by using the mode-superposition scheme. The calculated results are compared with the responses of rock dams.ª¤

Key words:concrete faced rockfill dams; shear wedge beam; seismi c response.

The effect of soil lateral dilation behavior on stress and strain of earth and rockfill dams

YIN Zongze
(1Hohai University, Jiangsu Nanjing 210098,China)

Abstract:The effects of soil lateral dilation behavior on the interaction between soil an d structure revealed by experiment and calculation. It helps to explain the caus e of the major error occurred in the stress calculation of concrete face-plate in rockfill dam and cutoff wall. Generally, the lateral dilation behavior of soi l can not be actually simulated in the constitutive model The investigation also shows that the anisotropy behavior of soil also plays an important role affecti n g the stressstrain relationship. It is suggested that anisotropy should be con sidered as an important problem in improving the constitutive model.ª¤

Key words:earth and rockfill dam; constitutive model; lateral d ilation behavior; anisotropy; concrete face-plate; cutoff wall.

Application of Gauss numerical integration to calculation program for non-circular arch dam

LI Zhanmei
(1Guizhou Provincial Water Conservancy and Hydropower Bureau,Guizh ou Guiyang 550002,China)

Abstract:A method for stress-strain analysis of non-circular arch dam by means of Gauss numerical method is proposed.In this method the inte gration variable intervals are treated by different way according to the feature s of arch dam.It is successfully applied to the analysis of five kinds of arch d am with different curvature including arch with 5 centers,parabolic,logarithmic spiral,elliptic and hyperbolic.

Key words:Gauss numerical integration method; variable; interval;non-circular arch dam; multi-arch and cantilever method.

Study on mechanism of ice jam formation in Bayangaole section of Yellow River

KE Sujuan,LU Guangqi,REN Zhiyuan
(1Bureau of Hydrology, YRCC,Zhengzhou 450004£¬China)

Abstract:Bayangaole section is located at the upper reach of Yellow River. Ice jam always happened in winter at this section since 1986 and formed s erious disasters. In this paper, the variations of hydraulic factors,thermal fac tors as well as the boundary conditions of channel are analyzed in detail and th e causes and conditions of ice jam formation are studied.

Key words:Bayanaole section; Yellow River; ice jam; formation; mechanism

Sodium adsorption ratio and its application to appraisement of alkali characteristics of water

SONG Xinshan,DENG Wei,ZHANG Guangxin£¬YAN Baixing
(1Changchun Institute of Geography, CAS, Changchun 130021,China)

Abstract:According to the test data, the characteristics of Sodium Ad sorption Ratio(SAR)for water in west part of Song\|Nen Plain are studied systema tically. The study result shows that SAR is being highest in lake and lowest in confined water. Furthermore, the relationship between the Ratio calculated from the concentration of Na^£«, Mg²⁺or Ca²⁺and the Ratio affected by ions in solution is revealed according to the statistic result. The Ratio af fected by carbonate acid equilibrium is also studied. The relationship between S AR and pH are explored and the methods for claculation of SAR are analyzed. On t his basis, the appraisement on the feasibility of suing the water in west part o f Song-Nen Plain to irrigation is given according to the calculation results an d Richard's grade standard.ª¤

Key words:Sodium Adsorption Ratio; alkali water; appraisement; c arbonic acid equilibrium

Effects of flood discharge and regulation of power load on operation of vertical ship lift in hydropower station

XIE Peizhen
(1Fuzhou University, Fuzhou 350002, China)

Abstract:The effects of unsteady flow downstream the hydropower station dut to flood disc harge and load regulation on the operation of ship lift are studied in a hydraul ic model test. The factors affecting the wave heights in ship compartment and na vigation channel, the time period from peak power regulation to the arise of max imum wave height and the duration for water surface reaching a steady level are investigated. Furthermore, the probable maximum and minimum water depths in ship compartment and in navigation channel, the maximum and minimum water weight in compartment as well as the maximum water surface slope and velocity are studied. ª¤

Key words:vertical ship lift; power load regulation; ship compar tment; flood discharge; wave height; wave amplitude

Calculation method for optimization of steady flow in water supply network

CHENG Weiping, BAO Zhiren
(1Zhejiang University,Hangzhou 310027,China)

Abstract:In this paper,the solution of steady flow in wate r supply network is converted into a problem of an unrestrained optimization.By the analysis on target function,the uniqueness of solution is proved.An approach to solve the multisource network by constituting virtual node is proposed.

Key words:steady flow; network; water distribution; optimal model

Solution for conservative equation of 2-D shallow flow by using revised SIMPLE algorithm

HAN Longxi
(1Hohai University,Nanjing 210098,China)

Abstract:Based on the relationship between velocity and depth in SIMPLE algorithm,a improved formula for velocity correction of 2-D shallow f low is deduced.The computational result of flow in prismatic channel is given fo r demonstration.

Key words:2-D shallow flow; conservation form; SIMPLE algorithm; ve locity correction