Experimental and Numerical Analysis for Earth-Fill Dam Seepage

In this research paper, a seepage flow through a non-homogeneous earth dam at various hydraulic heads was computed by using finite element-based software (SEEP/W) and the simulated results were compared with the field observation respectively. The research work was executed on a Fontaine Gazelles dam, which is an embankment dam situated at about 35 km, northeast of Biskra province, Algeria. The outcome of the simulated results showed that the dam is safe against piping for all the scenarios, at its original design as the installation of a cutoff wall found working effectively in reducing internal pore water pressure within the dam and its foundation. The overall maximum and minimum seepage flow was recorded at the pond level 383m (5.04920 LPS) and 374m (2.100 LPS) respectively. The performance efficiency of the model was founded as 99.924%. The RMSE, MAE, and AMRE were found (0.0342015 LPS), (0.00511668 LPS), and 1.06667% respectively; which indicates that there was no major variation between observed and simulated seepage values.

The present research work is designed to model seepage analysis of an earthen dam by using finite element approach. For this purpose a research study was conducted on Hub dam, which is a small earthen dam located at about 35 km, north-east of Karachi city, Pakistan. In the study the amount of seepage through and under body of the main dam is computed, profile of phreatic line is simulated for different scenarios and compared with the observed data. For the purpose of this study, SEEP/W the sub-program of Geo-Slope software is used. Data pertaining to design parameters and dam geometry are given as input to the software to compute the unknown parameters. Finally results are validated by comparing them with the observed data. The main dam is composed of three different kinds of reaches; therefore in this research only one reach with core wall i.e. Zoned Embankment Section at CH: 48+75 is studied. Computations are carried out for three different scenarios, that is: maximum pool level, normal pool level, and minimum pool level.

Engineering, Technology & Applied Science Research, 2022

This study presents the seepage patterns of earth-fill dams, using critical situations by employing the finite element approach. The Nai Gaj dam is 65km northwest of Dadu city in Sindh Province, Pakistan. In this study, the seepage through the main dam body and foundation is computed and simulated for different scenarios, i.e. maximum, normal, and minimum reservoir level. Seepage analysis was conducted by using the SEEP/W sub-program of GEO-SLOPE software. Dam design parameters and dam geometry data were used as input data to compute the unknown seepage. The seepage behavior of the Nai Gaj dam is shown in terms of net flow which consists of equipotential lines, streamlines, velocity vectors, and phreatic lines. The results show the seepage flux, maximum seepage, and exit gradient at different reservoir levels. The results show that the average flow rate at normal, maximum, and minimum reservoir levels are 1.49×10-7cumec/m, 3.38×10-7cumec/m, and 2.108×10-8cumec/m respectively. In add...

2nd International Conference on Civil Engineering: Recent Applications and Future Challenges (ICCE2021), 2021

In the conditions of severe climatic changes that are sweeping the world now, causing many problems, of which high surface water levels, torrential rains and floods are among the most dangerous phenomena. Since dams are the most engineering and structural protection means that engineers resort to, to protect against these dangers in such circumstances, not to mention the other important uses of dams such as storing water for irrigation purposes, generating electricity, feeding the underground reservoir, or diverting flow paths for any engineering purpose. Dams are usually classified on the basis of several considerations, including solid dams of different types, and flexible dams. Flexible dams, which are sometimes called earth dams, are of a special nature as they consist mainly of loose materials of a special porous nature and different ratios of interspaces that allow water to pass through them and penetrate the dam body in different proportions, which, if not prevented or avoided, may lead to the collapse of the dam body. In the present study a numerical analysis of seepage through zoned earthen dams is introduced, as they are the most popular type of flexible dams, to clarify the behavior of the streamlines of the seepage water through the body of such type of dams with different types of used soil of filling materials. Decreasing the relative permeability coefficient between the inner and transition zones up to 0.001 caused a significant decrease in the different seepage properties, after that, the effect was minor.

The study of seepage through earth-fill dams is very important for the constructed dams to ensure that the control of seepage is sufficient for the safe and sustainable operation of the dam. It is also important in the design and construction of new dams to ensure that the seepage through and under the dam will be well controlled. Construction horizontal, inclined, trapezoidal or pipe filters one of the dam protection methods. Cut off also can be constructed to minimize seepage discharge directed to the downstream face of the dam. Seepage through an earth dam with internal cut off is experimentally studied in the laboratory of Irrigation Engineering and Hydraulics Department, Faculty of Engineering, Alexandria University, Egypt on a Hele-Shaw model. Also, using computer program SEEP/W (which is a sub-program of Geo-Studio). The experimental and numerical analyses of seepage through earth-fill dam with internal cut off is conducted. Results from solutions are compared with each other.

World Applied Sciences Journal, 2013

Geostudio software is one of geotechnical program that is based on the finite element and can consider analysis like stress-strain, seepage, slope stability, dynamic analysis and also fast water drop in reservoir. In this research seepage analysis in ilam earth fill dam has been done by seep/W software. In order to evaluate the type and size of mesh size on the total flow rate and total head through the dam cross section, four mesh size such as coarse, medium, fine and unstructured mesh is considered. Result showed that average flow rate of leakage under the different mesh size for ilam dam equal 0.836 liters per second for the entire length of the dam. Slope/W software is used under different conditions to evaluate slope stability. Analyzes for each state and each slope with Bishop, Janbu, ordinary method of slides and Morgenstern methods is calculated that the minimum safety factor in each of these methods, be considered as a safety factor of slope stability.

This investigation concerns to study the quantity of seepage through homogenous earth dam without filter resting on impervious base using computer program SEEP/W (which is a sub-program of Geo-Studio). Using SEEP/W experiments carries out with three different downstream slopes of the dam, three different upstream slopes, three variable downstream head, three different upstream head, three different height of earth dam and three different top width of earth dam. For each run the quantity of seepage have determined. Dimensional analysis was used with helping of the theoretical results to develop an empirical equation in order to determine the quantity of seepage through homogenous earth dam without filter resting on impervious base. Also, Verify the SEEP/W results with an artificial neural network (ANN), and compare with analytical methods. Results show that when compare the suggest equation with artificial neural network (ANN) less than 3% error with SEEP/W results less than 2% error, Dupuit's solution has more than 20% error and Casagrande's solution has more than 15% error. Nomenclature q = Discharge (L 3 /T) b = Top width of earth dam (L). H = Height of earth dam (L). h1 = Upstream reservoir head (L). h2 = Downstream reservoir head (L). k = Hydraulic conductivity of dam soil (L/T). FB = Upstream free board of earth dam (L). FD=Downstream free board of earth dam (L). = Angel of downstream slope. = Angel of upstream slope.

Engineering and Technology Journal, 2016

This investigation concerns to find a new equation for computing the quantity of seepage through homogenous earth dam with horizontal toe drain. For this purpose the computer program SEEP/W (which is a sub-program of Geo-Studio) was used. The SEEP/W runs were carried out with three different downstream slopes of the dam, three different upstream slopes, three variable horizontal toe drain lengths, three different free board, three different top widths and three different heights of the dam. For each run the quantity of seepage was determined. The results show that the seepage discharge increased with increasing upstream slope, downstream slope, upstream reservoir water depth and length of horizontal toe drain. Also, the results show that the seepage discharges decreased with increasing the top width of the dam and the height of the free board. Using SEEP/W results with helping a dimensional analysis theory, a new easy and reliable empirical equation for computing seepage discharge through homogenous earth dams with horizontal toe drain was developed. The analysis of the results by Artificial Neural Network (ANN) shows that the length of horizontal toe drain (L) is the more geometrical variable affect on the seepage discharge, while the upstream slope (tanθ) of the earth dam has a little effect.

world applied science , 2010

s: Generally, scientists and engineers use different methods to enhance safety and decrease any errors in calculation due to maintenance of water storage especially hydro structure of the dam. It is necessary to investigate the dam seepage control; commonly used by several methods. Seepage is one of the important issues for design, build and maintenance of dams awareness. Seepage problem and its rules helps scientist to select a suitable method of monitoring and solving such problem. These methods of analysis were carried out at civil and construction project. In this study, one of latest method of investigation of seepage behavior were analytically evaluated and compared with the actual rules. Based on determine results; several suggestions and optimization method were suggested. Therefore, an optimum method was scientifically selected. Besides that, flow condition of porous environment with application of numeric program was analyzed. Finally, all the results were lunched out from seep/w soft which is the most significant program about this matter; use of finite elements method is specified for saturated and unsaturated environment. Thus; leakage and seepage were defined as function of (time and position). Subsequently, the best seepage solutions for the dam constructing were scientifically identified.

In this study, a homogeneous section of an earthen dam (Hub dam) with and without cut-off wall was analyzed by using FEM based software SEEP/W. The FEM model was run to compute the behavior of the dam in terms of seepage flux and exit gradient for three different scenarios i.e. maximum (346 ft), minimum (270 ft), and normal pool level (339 ft) respectively. The simulated results for case (i) with cut-off wall showed that the dam is safe against piping, at its original design with overall minimum seepage flux of (2.513 x 10-4 ft3/sec/ft) and exit gradient (0.351) at downstream toe respectively. However, for case (ii) without cut-off wall, the dam showed abnormal behavior as an overall extremely high exit gradient (1.879) along with the maximum overall seepage flux of order 17.182 x 10-4 ft3/sec/ft respectively. The comparison showed that seepage flux (29.382% – 76.946%) and exit gradient (68.604% – 75.845%) through the dam and its foundation was found more when there are no cut-off walls. Which is the result of continuous movement of the water within the dam especially in the foundation, as there is no any barrier installed to control internal pore water pressure, due to which the water seeping from the upstream and foundation finds its way moving towards the downstream and cuts the toe to make its way out respectively.