Abstract: A back analysis method for rock mass parameters on the basis of real-coded genetic algorithm, according to the system identification theory, is proposed. The result of case study shows that this method is effective in determining the parameters of rock mass constitutive model and material properties.
Key words: genetic algorithm; constitutive model; parameters; back analysis.
Study on biodegradation of PCBs in soil-water-microbes system
LIU Ling, CUI Guangbai, HAO ZhenchunAbstract: Based on the mass-balance theory, a comprehensive mathematical model, concerning the effects of diffusion, sorption/desorption, biodegradation, especially the intraparticle irreversible sequestration, has been developed in this paper in order to predict organic chemical biodegradation in remediation site. Model simulation results match successfully with the field data of bioremediation processes in LTU sites on Alcoa′s Massena, New York. By using this model and theoretical analysis,2,3,4, and 5-Cl-PCBs biodegradation processes and regularities including the treatment time and extent in remediation sites have been predicted in this paper.
Key words: polynuclear biennials; biodegradation process; sequestration.
Formula for computing bending moment caused byice cover during lowering of pool level
LI Hongsheng1, ZHANG Xiaopeng1,
LIU Zengli1, SUN Jiangmin2
(1.Dalian University of Technology;2.Institute of Irrigation Science Research of
Heilongjiang Province, Harbin)
Abstract: A formula for calculating bending moment acting on the dam slope caused by ice cover during lowering of pool level is established. In this formula the gravity of ice plate is regarded as distributed load and the restrain conditions between dam and ice cover as well as the characteristics of ice are taken into consideration.
Key words: ice cover; dam slope; formula; bending moment; pool level lowering
Abstract: This paper presents a new large-scale system model for Yang he River in Hebei Province, China, which includes a multi-dimension, multi-objective dynamic programming model, a flood dispatching model and a water quality model. A new algorithm of discrete differential dynamic programming with changeable penalty term is put forward. The results of case study show that the mathematical model and its solution techniques are feasible and effective in practice.
Key words: sustainable management; water quantity; water quality; multi-dimension multi-objective dynamic programming; reservoir
Key words gravity dam; primary section; stress; stability; optial design
Abstract Based on the production function of economics, an econometric model for analyzing industrial water use is established. In the model, water(or water resources)is regarded as one of the elements of production to be integrated into the function together with fund and labor. The water use in Beijing is analyzed as a case study.
Key words industrial water use; econometric analysis; margin value; output elasticity; Beijing
Abstract: On the basis of the calculation of seepage flow caused by wave action, a method for analyzing the stability of revetment blocks in sea dyke is proposed. The reliability of the formula for calculation is verified by hydraulic model test in wave flume.
Key words: sea dyke; stability; stone block;seepage flow; wave action; formula
Abstract This article brings up the necessity of further study on the third principle of sliding stability analysis and the reasonability of adopting this principle is demonstrated on the basis of test data in situ.It has been emphasized that this principle is especially suitable to the rigid body limit equilibrium calculation in sliding stability analysis of discontinuous plane strengthened by concrete block in dam foundation.It is suggested that the allowable shear-friction factors of safety in design standard should be reduced.
Key words concrete block; sliding stability; shear-friction factor; dam foundation.
Abstract: This paper deals with the impact of soil erosion on flooding and drought in Hunan Province. It is shown that the long-term soil erosion has enlarged the natural disaster-causing capacity of flooding and drought. Under the similar climate condition, the forming of runoff is accelerated, the quantity of flood is increased, runoff coefficient becomes larger and the duration of high-water level in river or lake is lengthened during high-water period. Contrarily, the runoff is decreased and the duration of water-shortage in land surface is lengthened during low-water period. As a combination of these effects, the occurrences of flooding and drought are alternative and the disasters are aggravated.
Key words: soil erosion; disaster-causing capacity; impact; enlarged disaster
Study
on measures for improving the performance of concrete
in face-plate of CFRD
Abstract: In this paper, the measures for elevating the crack resistance, impermeability and durability of concrete for face-plate in CFRD, 200m in height, are experimentally studied. The results show that the adoption of triple composite additive, Grade I fly-ash, siliceous power and relvant agent for enhancing its strength, synthetic fiber as well as steel fiber are effective in improving the properties of concrete.
Key words: face-plate; CFRD; interface transitional zone; porosity; modifier
Abstract Flaring peirs with unusual configuration are used to combine with flip bucket to enhance the energy dissipation of the overflow discharge of Baishi Dam.The result of hydraulic model test shows that this kind of energy dissipaton is very effective.
Key words unusual flaring pier; energy dissipation; flip bucket; model test.
SHAO Xiaohou1, WANG
Jinbo2, LIU Cailiang1, LIU Xinren1
Abstract: In this paper, the data of field drainage experiment in Shanghai polder area and the data of lysimeter control test in Nanjing polder area are analyzed. The result shows that waterlogging reduction index for winter wheat and barley in the plain polder areas along Yangtze River is being 8∶2(ratio of water to air) in root accumulating zone (h=0～60cm) after 3 days of raining. The optimum economic ground water table for high yield is being 0.86m.
Key words: lower reach of Yangtze River; polder area; winter wheat and barley; criterion; waterlogging reduction
Abstract: Based on the theory of extensive angle analysis for slope stability, the equivalence surface method adopting disturbed energy as the criterion is proposed. In this method, stability safety coefficient is derived from the ratio fo internal energy to external energy and the minimum disturbed energy equivalence surface is established, which can be used to determine the potential sliding surface.
Key words: stability analysis; extensive angle; disturbed energy; equivalence method
Abstract: In this paper, a conceptual-stochastic model for predicting the dynamic variation of soil water storage in crop root zone was established. In the model, the stochastic potential evapotranspiration process was incorporated into a soil water balance equation of the root zone, thus a time dependent, stochastic differential equation was derived. Furthermore, the Fokk-Planck equation corresponding to the differential equation was derived and solved numerically. The probability density distribution, mean and standard deviation of soil water storage in root zone were obtained. The comparison of predicted mean and confidence band at 95% with the measured soil water storage shows that the model is effective in soil water storage prediction.
Key words: stochastic model; soil water; prediction; evapotranspiration
Abstract: Based on theoretical analysis and field data of cross section velocity distribution measured at 6 hydrological station,a formula for predicting the flow longitudinal dispersion coefficient in the Three Gorges Project reservoir is proposed.
Key words: longitudinal dispersion coefficient; prediction; TGP; reservoir