Numerical Analysis of Seepage in Earth-Fill Dams

Nassrin Jassim Hussien Al-Mansori,Laith Shaker Ashoor Al-Zubaidi,Thair Al-Fatlawi Jabbar Mizhir Al-Fatlawi,Nariman Yahya Othman

doi:10.28991/cej-2020-03091552

Nassrin Jassim Hussien Al-Mansori, Laith Shaker Ashoor Al-Zubaidi + Show 2 more

Open Access

https://doi.org/10.28991/cej-2020-03091552

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Abstract

In an earth-fill dam, the effect of seepage has been studied by applying a finite element method using the SEEP2D program. This is in order to determine the quantity of seepage through the dam. The total head measurements, core permeability, and anisotropy ratio (kx/ky) (Case study: Khassa Chai Dam, Iraq) are taken as the main parameters. The effect of the different water heads of the reservoir were tested on the seepage. The results showed that any increase in the water heads caused an increase in seepage quantity. Also, it was found that the seepage rate decreases by about 8.7%, 13.2%, and 15.3% at levels of water 454, 471, and 485 m.a.s.l, respectively by changing the core permeability from 10-6 m/s to 10-7 m/s. It has been concluded that the clay core plays a significant role in decreasing the seepage quantity and existing gradient. The results of testing the effect of anisotropy ratio on seepage showed that an increase in (kx/ky) ratio leads to an increase in seepage quantity. Output variables and input variables have been linked by the ANN model that governs seepage quantity through zoned earth dams and existed gradients. The results showed that both models present a good estimation for the determination of coefficient R2 (0.9003, 0.933).

Highlights

An earth-fill dam, which is viewed as a dike dam, is assembled primarily of compacted earth neither homogeneous nor zoned and contains in excess of 50% earth-fill
Out of all the numerical methods, the finite elements method appears to be the most powerful and efficient tool to solve a wide variety of practical problems [14]
Seepage quantity through zoned earthen dams decreased by about 61.3% when the height of water decreased from 485 m.a.s.l to 454 m.a.s.l

Summary

Introduction

An earth-fill dam, which is viewed as a dike dam, is assembled primarily of compacted earth neither homogeneous nor zoned and contains in excess of 50% earth-fill. As a result of the materials situated in the assemblage of the dam, drainage occurs through the dam's body. Leakage can happen under the dam establishment as well. In this examination, leakage through the dam's body was researched. Drainage in the Khassa Chai Dam utilizing the SEEP2D program to demonstrate the impacts of leakage under various water conditions has been investigated. Obaid (2002) presented a finite element procedure for determining the time dependent locations of the free surface, seepage heads, and pore pressures within the dam body. A numerical solution using finite elements method (Galerkin method) was employed to predict the piezometric head distribution, pore water pressure, seepage quantity, and the location of the free surface profile [2]

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