Abstract: Appropriately setting up diversion grid in curved channel can effectively control the generation and development of helical flow, shorten the distance for longitudinal velocity distribution adjustment and uniformly reallocate the flow momentum in the cross section quickly. Based on the model test, the relationship of diversion grid shape and uniformity of momentum allocation as well as the relationship of optimal momentum allocation and complicated geometrical factors of diversion grid are investigated.
Key words: curved channel; diversion grid; momentum allocation; dimensionless flow intensity
ZHOU Shi-qiao1,S.Hashimoto2,M.Nakawo2,H.Narita3
(1.Hunan Normal University; 2.Nagoya University;3.Kokkaido University)
Abstract: Based on the non-capillary model, this paper presents the modeling of the whole percolation process in snow including the melting of surface snow and water percolation. The comparison of calculation results with experimental data shows that the non-capillary model is valid only when the water flux is larger than 0.05cm3/cm2/h.
Key words: snow;melt water; percolation; mathematical modeling
ZHANG
Yan-hong,DU Xiu-li,ZHANG Bo-yan
(China Institute of Water Resources and Hydropower Research)
Abstract: Based on the uncoupled method for numerical simulation of near-field wave motion and stochastic finite element method, a new uncoupled method is proposed to analyze the seismic response of soil-structure system in time domain considering the stochastic characteristics of medium. By using this method, the radiation effect of wave energy to infinite field is simulated and the stochastic characteristics of complicated medium are being considered. This method is applied to analyze the earthquake response of the arch dam in Xiaowan Project。
Key words: numerical simulation; near field; wave motion; stochastic characteristics
XU Gao-tian1,
WEI He-ping2
(1.Shanghai University; 2.Tongji University)
Abstract：The diffusion characteristics of single port buoyant jet in the near field under the condition of flowing water are studied by using the method of solving the integral control equation.The relevant coefficients are determined according to the experimental data from model test.The mathematical model for single port buoyant jet is established accordingly.
Key words：buoyant jet; dilution; dispersion; single port; mathematical model; current; entrainment coefficient
JIN Feng,JIA
Wei-wei,WANG Guang-lun
(Tsinghua University)
Abstract: A 2-D dynamic model coupling the deformation block distinct element method with boundary element method in time domain is established. The model simulates the static and dynamic responses of discontinuous rock and the effects of infinite domain simultaneously. It can be used to analyze the static and dynamic stability, deformation of rocky slopes as well as the underground structures, especially when wave propagation input of earthquake and radiation damping must be taken into acciunt. The results of bench mark problems show shows that the precision of this method is high.
Key words: distinct element method; boundary element method; coupling model
LU You qing,PENG
Hong
(Nanjing Automation Research Institute)
Abstract: The mechanism of various prevention measures for arch dam foundation seepage in Shimen Project is revealed based on the analysis of observiation data.The safety of the dam is evaluated and the measures for further promoting the seepage prevention measure are investigated.
Key words: seepages;uplift level;seepage discharge;curtain grouting;drainage hole
WU Yong-sheng1,
LIAN Ji-jian2, ZHANG Qing-he2, QIN Chong-ren2
(1.Tsinghua University; 2.Tianjin University)
Abstract：Based on turbulent model of wave-current combined flow,a 2-D mathematical model is developed to simulate the time average velocity distribution.The flow structure within and outside the boundary layer under the interaction of flow and wave is calculated.The result shows that the Euler time average velocity outside the boundary layer will be decreased if the wave and current are in the same direction;contrarily,the velocity will be increased if the wave and current are in the opposite direction.The validity of the calculation result is verified by experimental data.
Key words：interaction of wave and current; time average velocity; distribution; following current; opposing current.
CAO Wen-hong, HE
Shao-ling, FANG Chun-ming
(China Insitute of Water Resources and Hydropower Research)
Abstract: In consideration of the rapid migration of coastline and great variation of sediment concentration in Yellow River estuary, a 2-D numerical model for unsteady flow and sediment transport is developed. Verification demonstrates that the model can effectively simulate the sediment transport, scouring and silting of seabed and the variation of coastline.
Key words: Yellow River; estuary; sediment carrying capacity; narrow slot method; unsteady flow; numerical modeling
WANG Yu
(Yunnan Geological Survey Institute)
Abstract: According to the hydro geological features the karst hydro geological divisions in Yunnan Province can be divided into four basic categories:inter mountainous basin,depression,valley and deep buried.The suitable modes for exploitation of karst water in these divisions are proposed.Furthermore,the karst region in Yunnan Province is divided into five districts,according to the geological condition and exploitation condition of groundwater.The assessment of exploitation condition for each district is given in this paper.A proposal of effective exploitation and utilization of karst water is suggested.
Key words: karst water;hydro geological unit;exploitation condition assessment
WANG
Bao-tian1, ZHANG Fu-hai1,WANG Bin-qi2
(1.Hohai University;2.Guangdong Design and Research Institute for Navigation Channel)
Abstract: The construction and quality inspection method for large size gravel columns reinforcing the very soft river slope are introduced.The relation between shear strength and area replacement ratio,relation between over charged coefficient and load current,as well as the load time are obtained from field experiments.The safety factor of a canal slope under construction is calculated by using the shear strength obtained from experiments and is in accord with the need of code.
Key words: large size gravel column;shear strength; very soft river slope;field experiments
CAI Yuan-qiang，QIAN Lei,LING Dao-sheng,WU
Shi-ming
(Zhejiang University)
Abstract: The Liquefaction characteristics of loose silt in embankment of Qiantang River are studied by dynamic triaxial test and vibration column test.Based on Biot's dynamic consolidation theory,the calculation programs for dynamic response and effective stress analysis are developed, in consideration of the non-linear and damping effect of soil.The stability analyses of the embankment under the conditions of two types of Ⅶ degree earthquake and three typical levels are conducted.The calculation results verify that the embankment is safe.
Key words: earthquake;liquefaction;stability analysis;permanent deformation
JIAO Xi-yun1,
WANG Wen-yan2, LEI Zhi-dong1, ZHANG Jiang-hui3
(1.Tsinghua University;2.Xi'an University of Technology;3.Xinjiang Institute of Water
Research and Hydroelectric Power)
Abstract: A improved Maheshwari method for estimating infiltration patrameters of soil is proposed.A simple formula for estimating the infiltration parameters is derived referring to subsurface shape factor expression developed by Fok & Bishop.The results indicate that the filtration parameters using the improved method developed by the authors are much the same as that derived from Maheshwari method.Furthermore,the influences of surface shape factor on estimation of the infiltration parameters are analyzed and the results indicate that the subsurface shape factor can be assigned as 0.75.
Key words: surface irrigation;infiltration parameters;surface shape factor;subsurface factor
LU Jing-zhou1,
LIN Gao1, XIAO Shi-yun1, WANG-Zhe2
(1.Dalian University of Technology;2.Northern Jiaotong University)
Abstract: The damage trial of concrete cube is experimentally studied.The combination of lateral stress and maximum vertical strain denotes the loading history and the reduction of tensile strength and the descent of ultrasonic velocity denotes the damage of concrete.The laws of damage initiation and development,under the conditions of monotone loading,cyclic loading and varies confinement pressure are investigated.According to the fitting of experimental data,the evolution equation of damage is obtained.The main factors affecting the damage development are examined and the causes are expounded.It is concluded that this method is feasible.
Key words: concrete;damage;tensile strength;loading history;ultrasonic velocity
DING Liu
qian,ZHOU Xiao guang,YANG Kai hong,CHAO Hua yi
(China Institute of Water Resources and Hydropower Research)
Abstract：The seepage of CFRD joints is studied by using finite element calculation and complex variable function. The analytical equations of seepage quantity and gradient are deduced. The equations are applied to calculate the seepage of siltation self healing watertight of 233m high CFRD in Shuibuya Project.
Key words：CFRD；feasibility；siltation self healing watertight;FEM;complex variable function
LIU Qing-ren
(Heilongjiang Hydraulic Research Institute)
Abstract：The effect of adjustment on flood forecast according to the extraordinary variation of astronomy and maritime factors in flood season is investigated.It is found that the principle of long term hydrological forecast based on the interaction among sun,ocean and earth is believable.It is demonstrated that the adjustments of flood forecast according to the extraordinary variation of sunspots and other astronomy phenomena are very important.
Key words：flood forecast; extraordinary variation; astronomy factors; maritime factors; adjustment
DU Lihui1，HUANG Liqing2
(1.Tsinghua University；2.China Institute of Water Resources and Hydropower Research)
Abstract: In this paper, the nonlinear axisymmetric finite element method is adopted to analyze the stree strain of surrounding rock of vertical tunnel in the process of excavation and lining. The failure approach concept is introduced in the discrimination of the non linearity and failure of the rock. The softening of the rock and the types of failure are simulated and the creeping of the tunnel is analyzed.
Key words: axisymmetric finite element; nonlinear; creeping; excavation; lining; numerical simulation
ZHANG Xi-ying,
PEI Dong, YOU Mao-zheng
(Institute of Agriculture Modernization,CAS)
Abstract：Results from four years' field experiments show that water deficit and deficit degree during different growing stages of winter wheat greatly affects its grain yield production and water use efficiency.Optimum irrigation scheduling can be set up based on the required soil water contents and the lower limit of soil moisture for different growing stages.Generally,in the piedmont of Mt.Taihang 3-4 applications of surface irrigation is needed for winter wheat each season.While by applying the optimized irrigation schedule,one application during wet years,two in normal years and three in dry years will achieve maximum yield and water use efficiency.Grain yield increases by 7%-11% and WUE by 11%-24%.This amount of water saving is very important to this region.
Key words：winter wheat; soil moisture criteria; optimum irrigation scheduling