Papers by Keyword: Earth Dam

Abstract: The numerical analysis using finite difference method to study static and dynamic performance of embankment dams is a complex process, in which the materials behavior, soil-dam foundation interaction, hydraulic conditions and saturation effects, should be taken into account. In this study, static and dynamic analysis of Keddara earth dam, located in Boumerdes region (Algeria), is conducted by a numerical analysis using finite difference method (FLAC 3D), with the objective to define its behavior in terms of settlement, strain and pore pressure variation, during its construction and operation. Two stages are considered; the dam construction stage and water filling stage. In this way, two mathematical models are considered for the static analysis; the elastic model and Mohr-Coulomb model. To conduct a coupled dynamic analysis a real earthquake record is used and the interaction between the fluid and solid phases is taken into account.

Abstract: Currently, there is a large amount of earth dams should be reinforced because of the running incessantly in a long period in our country. And the anti-seepage evaluation is an extremely critical and indispensable index to scrutinize the reinforcement effect of earth dam comprehensively. According to the real engineering conditions of the dam, the finite element seepage analysis method is used to compute the seepage characteristics in the Fengchan reservoir before and after the reinforcement in this paper. The results show that the effect of the anti-seepage system is well for adopting the concrete slope protection and concrete anti-seepage wall. The seepage state of foundation and dam body is improved evidently. The seepage gradient and seepage quantity of each material zone reduce significantly and meet the standard requirement of specification.

Abstract: After the introduction of the ANCOLD Guidelines on the dam design to withstand earthquakes in 1998, many dams in Australia have been reviewed on their capacity to withstand earthquakes. As results, many of them have been upgraded in the last two decades to increase their resistance against seismic loading. This paper presents the current methods used in Australia to undertake seismic upgrade for earth dams. The paper firstly presents brief discussion on the current methods of seismic stability assessment of earth dams. It then discusses the advantages and limitations of the available methods for seismic rehabilitation. Finally, it presents one of the case histories of seismic upgrade in Victoria, Australia.

Abstract: Monte Carlo simulation provides a probabilistic method to evaluate the physical behavior of earth dam. Therefore, the behavior could be got in a more realistic manner. Based on the theory, an innovative software program code is developed by combining the Monte Carlo and finite difference methods to predict the performance of earth dams after impounding. In order to assess the efficiency of the method, the case study of earth dam, located at Southeast of China, has been studied in detail. The performance of this dam is predicted and compared with the field monitoring by using the monitoring data. The results shows the robustness of the proposed method.

Abstract: In dam seepage line monitoring process, dam saturation line "inverted siphon" phenomenon appeared. In order to study the time effect, indoor model test were done. The dam seepage line rules and conditions were determined. The results show that when the reservoir water level dips, the dam seepage line with the decreasing of the water level will drop. But the changing has lagged far behind. Hysteresis and permeability dam, seepage path length, the upstream water level and other factors related to the rate of decline.

Abstract: A three dimensional numerical model for a typical earth dam and its valley site was established and the nonlinear seismic response of this model was performed. Experimental data of cyclic triaxial tests were adopted to determine the curves of modulus ratio and damping ratio that vary with dynamic strain amplitude. Free-field artificial boundary and viscous artificial boundary were employed and the input waves were the revised ground motions obtained from the station near the dam. Distributions of the PGA, displacement, residual deformation, shear strain increment and element failure state were presented. Results demonstrate that the 3D local valley site effect has a significant influence on the seismic response of earth dam.

Abstract: The unsteady seepage through earth dams is analyzed with the finite element method in this paper.Using this method, the seepage through Huangbizhuang earth dam is calculated. Many reasonable suggestions are posed to help the management and reinforcement of Huangbizhuang reservoir earth dam.

Abstract: The design “non-rope opening vertical interlock block” is used in the main dam of Linhuaigang Project for the first time in China. The opening of the block can effectively reduce the uplift pressure induced by waves. The vertical interlock can make block interlock three- dimensionally so as to enhance the integrity of the block and improve the anti-wave performance. The design can not only improve the protection of the main dam slope under long blowing distance and high wind and waves, but also save the use of stone and construction investment as well as protect the environment. Openings vertical interlock concrete block between the rigid in-situ concrete slope and the flexible dry stone slope, not only avoid the shortcomings of in-situ concrete slope suited to soft ground deformation, but also resist the larger storms owing to the better integrity than dry stone pitching ,from the interlocked effect between the blocks. Compared with the entity block, opening vertical interlock block thickness is reduced greatly. The earth dam project of Lin Huai Gang flood control project applied openings vertical interlock block successfully in water conservancy projects .The project has the pioneering position in the use in the wave elements of reservoirs, lakes and the other large water conservancy revetment constructions.

Abstract: There will be a variety of problems in the process of dam using. The common problem is that the saturation line is high. When the saturation line is too high, it will not only lead to the increase of downstream leakage, but it may also cause dam break and finally causing the loss of life and property. So we need to pay much attention to the saturation line of the dam. When the saturation line is too high, it should be noted and if necessary we should adopt the measures of strengthening. This paper through the comparison and selection of several schemes and finally to determine the reasonable reinforcement method.

Abstract: This paper analyzes the problems which exist in finite element calculations of the earth dam seepage which is free surface solution, cell subdivision improper, the transformation of the free surface boundary conditions and the permeability coefficient values at the interface of different materials, boundary conditions and other issues. Put forward the corresponding solution. Applies common general finite element software to calculate the seepage. Works in conjunction with a stable levee seepage analysis and get better results.