| IHWR CWSnet |
Journal of Hydraulic Engineering |
CONTENTS [Chinese] |
The Calculation Method for Shear Strength of Saturated Soft Clay Under Impact Load |
Bai Bing |
(Wuhan Transportation University) |
Liu Zude |
(Wuhan University of Hydraulic and Electric Engineering) |
Abstract The variation of shear strength of saturated soft clay under impact load is studied.The effect of action history on the shear strength of quasi over-consolidated clay is analyzed.A model for predicting shear strength of soft clay is suggested.In the model the conditions of partial drainage and stages of impact are to be taken into account.The calculation results are in good accordance with the test data.
Key words saturated soft clay,quasi over-consolidation,re-consolidation index,shear strength,prediction.
Vibration of thin Rectangular Plates on Winkler's FoundationSubject to X-Direction in-Plane Forces |
Zhang Yingshi |
(Beijing Univerisity of Aeronautics and Astronautics) |
Abstract Differential equations for vibrations of simply supported thin rectangular plates on Winkler's foundation subjected to in-plane forces,are established.The general soluations are derived nd the expression of vibration mode functionis deduced.Forced responses of such plates under different loads are discussed with Fourier expansion of generalized functions.Influence functions for various cases derived in this paper may be used to solve the problems of static buckling and stability of these thin rectangular plates under the same conditions.
Key words Winkler's foundation,in-plane forces,x-direction,thin plate,vibration,forced response.
Fracture Parameters of Concrete Basedon the Ficititious Crack Model |
Wu Zhimin Xu Shilang Wang Jinlai |
(Dalian University of Technology) |
Abstract The pre-critical crack propagation length Δac of concrete is analytically evaluated by using the maximum load and critical crack mouth opening displacement measured in experiments by means of wedge splitting specimens.According to the analytical solution of Δac,the initiation fracture toughness KiniIc,unstable fracture toughness KunIc and the critical crack tip opening displacement CTODc of the wedge splitting concrete specimens are analytically determined and compared with the test data.The results show that the KiniIc,KunIc and CTODc are size-independent when the specimen height is larger than 400mm,and the double-K fracture criterion can well describe the cracking initiation and unstable fracture of cncrete structure.
Key words concrete,fracture parameters,crtical crack tip opening displacement,fictitious crack model.
He Wenjuan |
(Wuhan University of Hydraulic and Electric Engineering) |
Abstract The twist resistance of the main components, the effect of back tension member area on twist resistance, the variation of lifting force, the stress of the top pivot tension members as well as the effect of impact force on deformation and stress of the mite lock gates are investigated in detail by means of computation. Suggestions for improving the design of mite lock gates are given.
Key words mite lock gate, back tension member, raising force, top pivot member, impact force.
Wang Shuyu Liu Guohua Shi Jiaoying Dong Feng |
(Zhejiang University) |
Abstract The chaotic phenomenon in observation data of dam monitoring is discussed.The data series of observed vaules and their residual errors are reconfigured in phase space respectively and the observed values at the points of certain time delay are handled as new dimensions.Thereby phase points are formed.The dimension amount of the attractor can be calculated according to the correlation dimension method.The calculated results shows that the dimension of the attractor obtained is in the range from 3.1 to 3.5.It seem that the phase traces in the plots of observed values and residual error series are different from white noise trace.These indicate that the strange attractor may exist in the observation data series.
Key words observation data,dam monitoring,fractal dimension of attractor.
Preliminary studies on groundwater effectson SPAC system in shallow groundwater field |
Yang Jianfeng Li Baoqing Li Yunsheng Ma Rui |
(Institute of Geography, Chinese Academy of Sciences) |
Hong Baoxin |
(Tongzhou Agrohydrological Experiment Station, Tongzhou, Jiangshu Province) |
Abstract In order to evaluate the effect of groundwater on hydrological and biological process of soil plant atmosphere continuum in shallow groundwater field, two experiments are carried out at Yucheng Comprehensive Experimental Station and Tongzhou Experimental Station respectively.The results show that 15.69% of evapotranspiration is contributed by groundwater evaporation during milking stage of maize at Yucheng Station. Studies indicate an optimum water table depth for winter wheat at Tongzhou Station. Surface irrigation may be reduced when shallow groundwater is present.
Key words groundwater, soil plant atmosphere continuum(SPAC),hydrological process, biological process.
Experimental research on infiltration from single hole of membrane |
Jiao Xiyun Wang Wenyan Zhang Jianfeng |
(Xian University of Technology) |
Abstract The experiments of infiltration from membrane hole for five diameters are carried out in lab by using loam soil.Cumulative infiltration,wetted depth and wetted radius are observed.The results show that:1、The relationship between cumulative infitration of single hole and infiltration duration conforms to Kostiakov model;2、The relativity between the hole diameter and the relative infiltration parameter is significant,3、The wetted depth of membrane hole is less than that of vertical infiltration and the relationship between the hole diameter and the ratio of wetted depth of single membrane hole to wetted depth of vertical infiltratoin is obvious;4、The relation between wetted radius on soil surface and infiltration duration conforms to power function;5、The average moisture of the wetted soil for membrane hole infiltration is less than that for vertical infiltration.
Key words membrane hole, infiltration, cumulative infiltration, wetted depth,wetted radius on soil surface.
The optimum irrigation scheduling for rice with stochastic rainfallunder limited water supply |
Cui Yuanlai Yuan Hongyuan Li Yuanhua |
(Wuhan University of Hydraulic and Electric Engineering) |
Abstract Base on the analysis of water sensitivity parameters(WSP)of dated water production function for rice,the function of cumulative WSP,which can be used to calculate the WSP of different time period,was established.The optimum irrigation scheduling with stochastic rainfall for rice under limited water supply was investigated by using the stochastic dynamic programming (SDP) model.Real evaprtranspiraton,seepage and other water movements in the paddy fields have been considered in the SDP model.A case study shows that the SDP model is economical and feasible.
Key words water production function, deficit irrigation,irrigation scheduling,optimization,stochastic dynamic programming.
Numerical siiulation of groundwater TCA contamination and remediation at site |
Song Hanzhou |
(Hohai University) |
Allan D.Woodbury |
(University of Manitoba,Canada) |
Abstract A mathematical model describing TCA transport in an aquifer at an industrial site is solved by using GMS software package.It is assumed that the groundwater flow at the site is in steady state,while the solute transport is in unsteady state.Results obtained from the numerical simulation indicate that their is a net reduction both in concentration of TCA and in extent of the plume during the period of operaton.After continuous operation for three years the remediation efficiency reaches more than 80%.
Key words carbonate aquifer, TCA contamination,pump-and-treat,numerical simulation, performance assessment.
Cheng Xiaotao Lan Hong Li Na |
(China Institute of Water Resources and Hydropower Research) |
Zhang Yong Xue Yunpeng |
Abstract Based on the theories of 2 D unsteady flow and non equilibrium sediment transport, a 2 D numerical model for the simulation of flood routing and sediment transport along the lower reach of Yellow River is developed with non structural irregular grids. The calculated field of the model covers the main channel and floodplain from Huayuankou to Sunkou with a total length of 310km and area of 1340km2. The model is consisted of three section which operate as a whole. It possesses a plotting function and an interface that prompts the position and information of the dike when overflow occurred and allows the user to change the state of the dike. The model has a self regulation capability of scour and silt to suit the large variable range of flow and sediment content. The calculation procedure is checked by the observed data of two floods.
Key words lower reach, Yellow River, flow propagation, sediment transport, numerical simulation.
Yao Leihua |
(XianBranch,China Coal Research Institute) |
Abstract Perturbation-Coefficient Awaiting Determination Stochastic Finite Element Method(PCSFEM) for groundwater flow modeling is proposed.The formulas for the mean value and the variance of water head are derived.An example is given for illustration.
Key words ground water flow model, perturbation-coefficient awaiting determination, stochastic finite element method.
Comparison of three kinds of indices for calculating optimal irrigation quota |
Liu Wenzhao Shangguan Zhouping Fan Xingke |
(Institute of Soil and Water Conservation,CAS and MWR) |
Abstract In this paper the different optimal irrigation quotas according to the targets of yield per unit area,irrigation production efficiency and irrigation production elasticity reaching their maximums are compared.The relationship between crop yield and irrigation water amount is considered as a quadatic parabola.It is revealed that the irrigation quota by which the irrigation production efficiency reaching its maximum only exists in a condition of no crop yield in case of no irrigation.Contrarily,the irrigation quota by which the irrigation production elasticity reaching its maximum only exists if the crop yield could come from a rainfed land.
Key words irrigation quota, deficit irrigation, production efficiency, production elasticity.
The fractal characteristics of riverbed roughness with non uniform sediment |
Wang Xiekang Fang Duo |
(Sichuan University) |
Yiao Lingkan |
(Southwest Jiaotong University) |
Abstract Based on the analysis of stochastic distribution of non uniform sediment, the roughness function of the sediment is studied. The distribution of particles is simplified and the fractal characteristics of roughness with original and armoring riverbed are studied by means of fractal theory. The relationship between riverbed roughness and its fractal dimension is obtained according to the experimental data and compared with the relationship between roughness and representative diameter. It is believed that, the fractal dimension of initial riverbed has a better relationship with the roughness. It provides a new method to study the bed roughness, sediment incipient and transport process.
Key words bed roughness, armoring riverbed, fractal theory.
Nonlinear evolution model for horizontal propagation of wave in a two layer fluid |
Zhang Wanshun Li Yitian Fang Duo |
(Sichuan University) |
Abstract Based on the Boussinesq's assumption, a new form of nonlinear evolution equations for horizontal propagation of wave in two layer fluid are obtained. Equations can reach the forth order chromatic dispersal precision by means of taking optimum value with two parameters. The equation possesses higher numerical stability than that of the water depth averaged equation and can be used to model the nonlinear transformation of surface waves in shallow water due to the effects of shoaling, refraction and reflection.
Key words shallow water wave, evolution equation, two layer fluid.