Key words:dam simulating analysis; temperature stress; concrete creep; non-reverse creep.
A non-associated plastic constitutive model for concrete
WANG Zhe1, LIN Gao2
(1.Northern Jiaotong University, Beijing 100044, China;
2. Dalian University of Technology, Dalian 116024, China)
Abstract: Experimental results of concrete show that the initial yield stress is linearly dependent on stress when there is no deviatoric stress and the softening phenomena will emerge after dilatancy but not all softening is accompanied by dilatancy. On this basis, a non-associated constitutive model for concrete is established by means of semi-empirical and semi-theoretical method. The method has the properties as follows: stress-strain curve is smooth during monotone loading; the stress at peak point obeys the law of William-Wanke strength model for three parameters; the variation has a steady trend even in the softening period; volume compression and dilatancy can be well described.
Key words: plasticity; constitutive; concrete; non-associated; internal variable .
Abstract:The development and successful application of fiber optic gyro (FOG) supply the potential possibility for performing accurate slab deflection measurement. In this research, an algorithm method is put forward for calculating slab deflection based on the output of FOG and an in-door model test was conducted. Experiment reveals that FOG is applicable to structure deflectionmeasurement. Its measurement error is approximately 5%.
Key words:fiber optic gyro; slab deflection; measurement error.
Key words: fly ash and slag; chemical characteristics; storing; impact on environment.
Key words: expansive cement; concrete; expanding ratio; magnesia;ettringite.
Key words: solidification creep theory; concrete; discrete retardation time; continuous retardation time; continuous retardation; exponential
Influence
of specimen initial crack length on double-K
fracture parameter of concrete
Key words: concrete; crack; fracture parameter, fictitious crack
model.
A study on system reliability and expectancy of gravity dam in service
ZHANG Junzhi1 LI Guiqing2Abstract: Based on the study on structural system and according to the characteristics of gravity dam and service structure, the calculation method for system reliability and life expectancy of gravity dam in service are discussed in this paper. The variation of system reliability is analyzed by using an example and the problems pending for further study are outlined.
Key words: gravity dam; in service; system reliability; life expectancy.
Random-Critical theory of the macro shear strength
of concrete dam foundation surface
LAI Guowei LU
Shuyuan
(Wuhan University of Hydraulic and Electric Engineering, Wuhan 430072,China)
Abstract: Based on the theory of random fields and percolation theory, the formulas for determination of upper and lower limit of the macro shear strength of concrete dam foundation surface is deduced. By using these formulas the shear strength can be determined by the experimental result of small specimens.
Key words: dam foundation surface; shear strength; random field; critical condition.
Optimization of arch dam based on conception of fuzzy reliabilit
FENG Bohao1
ZHANG Junzhi2 ZHANG Lixiang1
(1.Yunnan Polytechnic University, Kunming 650051,China;
2.Nanchang College of Water Conservancy and Hydroelectric Power, Nanchang 330029,China)
Abstract: In this paper, a new optimization model based on statistic and fuzzy mathematics is developed. The strength safety is concerned in this model. The rationality of this model is illustrated by the calculated result of an arch dam.
Key words: optimization; arch dam; fuzzy reliability.
A game analysis approach of cost allocation for multipurpose water projects
FU Chun1,HU
Zhenpeng2
(1.Nanchang University, Nanchang 330029,China)
Abstract: In this paper, a new game means for analysis of cost allocation for multipurpose water projects is introduced. The efficiency and reasonability of this new means are illustrated by an ex-ample.
Key words: multipurpose water project; game analysis approach; cost allocation
Key words: gravity dam; FEM; diagonal tension stress.
SHEN Anzhen LI
Ligang
(Xiaolangdi Construction and Management Bureau,Jiyuan 454681,China)
Abstract: Aseries of new technologies for grouting are adoptedin the construction of Xiaolangdi Project.The technologies are:automatic recorder;stable mixer; adjustment of refusal criterion and new check method for consolidation grouting.
Key words: Xiaolangdi Project; grouting; automatic recorder; stable mixer; refusal critoerin; consolida-tion check method.
The evaluation of water uptake models by using precise field observation data
LUO Yi,YU Qiang,OUYANG
Zhu,TANG Dengyin, XIE Xianqun
(Institute of Geography, CAS, Beijing)
Abstract: In this paper, the macroscopic water uptake models widely used in modeling the water flow in soil-plant system are evaluated by using the precisely obtained evaptranspiration and soil water content da-ta from the lysimeter and the root distribution data obtained in the wheat field nearby. Meanwhile, the Molz-Remson model and Selim-Iskandar model are modified with the Feddes reduction function, and the Feddes model is modified with the root length density to account for the role of root distribution. Those models are incorporated into the soil water flow equations as extraction term. The flow equations are numerically solved with the measured evapotranspiration as input. The predicted and measured soil water content profiles are compared to evaluate the validity of the extraction term models. Results show that:(1)the average deviation of the molz-Remson (linear) model, Feddes model and Selim-Iskandar model got as high as 20%,and the Molz-Remson model 13%;(2)modifications made to the Molz-Remson model and Iskandar model did not achieve any improvement to the model behavior,but that to the Feddes model achieved a great success in lifting its prediction ability.
Key words: water uptake by root; soil water; winter wheat;evapotranspiration.