Papers by Keyword: Seepage

Abstract: In this investigation, the quantity of seepage through a homogeneous earth dam with a vertical drain on a permeable foundation was studied using the SEEP/W program. Moreover, the effects of the geometrical and geotechnical parameters (upstream slope, dam height, top width, free board, and permeability ratio) on leakage flow were analyzed with SPSS 20. To begin with, leakage flow values through an earth dam were estimated using SEEP/W by taking three values of each parameter, and then statistical analysis was performed with the help of dimensional analysis. In addition, an empirical equation and a neural network model dubbed q_ANN were developed to calculate leakage flow through an earth dam with a vertical drain. The validation of these models (empirical equation and q_ANN) is made by their applications to real case studies such as El-Haimeur and Boubrik dams located in Ghardaia City. In conclusion, the values of these models can prove that the performance of the models is high and accurate to predict leakage flow through a homogeneous earth dam with a vertical drain on a permeable base.

Abstract: Partial differential equations such as models for flow in unsaturated porous media are difficult to be solved when space-time variable boundary conditions are included. A general solution to this problem is discussed in this contribution and is devised in such a way that the face with variable boundary condition can be subjected to Dirichlet, Neumann or the so-called Signorini/ambiguous boundary conditions, considering the transition from one type to another. A method based on the enrichment of finite elements that is able to accurately model seepage with these complex boundary conditions is discussed. Simulations are presented illustrating the capabilities of the new method in 2D and 3D, including cases where the free surface varies due to rain.

Abstract: The functional relationship between rock and coal permeability and gas adsorption quantity has been determined, based on earlier experimental results. Then, by method of mathematical physics, the authors derived an analytical solution for a gas seepage equation in which the adsorption effect has been considered. This analytical solution could be used for developing the theory of Seepage Mechanics and Computational Fluid Dynamics, and for checking and correcting various numerical solutions as a standard solution, and for inspiring various calculating techniques such as difference schemes, grid generation, and others as well. The analytical solution derived in this paper has extremely important practical significance in conducting the arrangement of gas extraction operation in coal mine and the CBM (coal bed methane) development planning.

Abstract: Theoretical investigations on cnoidal waves interacting with breakwater resting on permeable elastic seabed are presented in this paper. Based on the shallow water reflected wave theory and Biot consolidation theory on wave-induced seepage pressure, the analytical solutions to first order cnoidal wave reflection and wave-induced seepage pressure are obtained by the eigenfunction expansion approach. Numerical results are presented to show the effects of depth of water, breakwater geometry on cnoidal wave-induced seepage uplift force and overturning moment. Compared with Airy wave theory, in certain shallow water conditions, the shallow water wave theory can more effectively illustrate wave nonlinearity effect in wave load prediction.

Abstract: In this paper authors haveconsidered potentially possible causes of failures in filtration mode offoundation. Methods of calculated prediction of abnormal seepage processesparameters have been considered.

Abstract: In this paper authors have considered existing mathematical modeling methods of filtration mode of large dam’s foundations using finite element method. Practical analogies for solving filtration equation have been described concerning the problems of hydraulic engineering. Recommendations for solution to filtration problems have been given based on use of general-purpose industrial CAE software.

Abstract: To simulate water flow in unsaturated porous media, analytical and numerical solutions of infiltration models have revealed the hydraulic and mechanical properties of partially saturated soil, such as the soil-water retention curve, shear strength, and permeability functions. Seepage, which is related to both the rainfall intensity and the saturated soil permeability, is a problem for partially saturated soils. In this study, a simple stage model in developed to represent vadose zone infiltration under a constant intensity into a homogeneous soil with an ideal suction profile; in this model, the saturated permeability is less than the rainfall intensity. The typical trends of the matric suction profile in a vadose zone during a rainfall are calculated via analytical methods. The model predictions agree well with both a coupled code (this study) and open/commercial codes (UNSAT-H and SEEP/W) for several soil types.

Abstract: In the present code, the embedded depth is determined on the multi-pivot support structure to consider the impact of seepage less, and it is verified by anti-seepage stability for single layer aquifer, while the embedded depth is determined not expressly provide for heterogeneity aquifer of the coefficient of permeability difference. However, in the northwest loess areas, the formation is complex, permeability coefficient is variations. To solve this problem, the arctic investigates change law that the impacts of embedded depth variation change on bending moment, the vertical displacement of bottom and maximum flow velocity under seepage, and made a qualitative research model. And the impact of seepage on the embedded depth cannot be ignored and a greater impact on the stability of the pit.

Abstract: The paper uses saturated - unsaturated seepage calculation of FEM, analyzes the seepage numerical of hongze lake dike reinforced by high-pressure Sway-sprinkle technology, provides seepage load for stress and deformation and stability calculation of the dike engineering, evaluates the anti-seepage effect of high-pressure sway-sprinkle cutoff wall. The results show that it reduced invasion of the embankment surface and decreased seepage velocity and flow, high-pressure sway-sprinkle cutoff wall took good effects and greatly improved the overall stability and safety of hongze lake dike.

Abstract: To meet the requirements of foundation bearing capacity, end bearing piles are adopted by most of the Sluices built on soft soil foundations. However, after the completion of the sluice, there will be settlements on both sides of the backfill, which will result in base cavity, form water seepage channels, and endanger the buildings and dams. In this paper, a new steel sheet pile diaphragm wall scheme is proposed to resit seepages under this situation. Steel sheet pile diaphragm walls are disposed on the river side of the building and connected with the chamber floor to prevent wound infiltration and sliding sideways. The practical results show the effectiveness of the proposed scheme.