الفهرس 
Groundwater FlowOnly 14 pages are availabe for public view
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Abstract
Sheet piles have an effective roles in controlling the solute transport for controlling the groundwater contamination. The aim of this study is an attempt to investigate numerically and experimentally using the sheet piles to control the contaminant transport from a point source through the horizontal layers of different permeability soil. The used modules in this work are two finite element programs as a numerical model as a part of Geo-Studio 2007 software package to study the solute transport in groundwater system for saturated soil in two dimensions. The first module (SEEP/W) is the flow module, which computes the water levels and piezometer heads. The second module (CTRAN/W) is the transport module, which studies the phenomena of contamination transport. Sand box model is used to verify the numerical model results by comparing the values of arrival times of a contaminant under the sheet pile (T1) and downstream of the sheet pile at the soil surface (T2). The considered parameters in this work are the head difference between upstream and downstream of the sheet pile (H), the sheet pile depth (d), the coefficient of permeability of the upper layer (K1), the coefficient of permeability of the lower layer (K2) and the distance between the sheet pile and the contamination point source (L). A good agreement is achieved between the results of the numerical model and the sand box model, where the mean deviation percentages equal to -5.6% and -5.97% for T1 and T2, respectively and the negative signal means that the CTRAN/W model is overestimates the results. The numerical model results for the two scenarios of the practical problems show that decreasing of the head difference by 25% leads to increase the dimensionless arrival time about four times the initial value for all considered values of the dimensionless depth of the sheet pile. The large value of d* and the smaller value of the distance L has a significant effect on the value of t* more than the small value of d* and the larger value of the distance L for case of the smaller value of K2 and the larger value of K1. While the small value of d* and the larger value of the distance L has a significant effect on the value of t* more than the large value of d* and the smaller value of the distance L for case of the larger value of K2 and the smaller value of K1. For the value of K2 less than 5×10-5cm/sec, it is noticed that increasing depth of sheet pile into the upper layer of low permeability has a great effect on value of t* and not needed to increase the depth of sheet pile into the lower layer at the small value of H that equals1.0m. For value of K2 more than 1×10-3cm/sec, it is noticed that increasing depth of sheet pile into the upper layer of high permeability has a slight effect on value of t* and needed to increase the depth of sheet pile into the lower layer at the large value of H that is more than 3.0m. Finally, the arrangement of the layers of the soil and their hydraulic conductivity affect the efficiency of sheet piles in the process of contaminant transport. In addition, dimensionless designed charts are prepared as a guide reference for determining the effective depth of vertical sheet pile with different permeability for the soil to improve the hydraulic performance of the remedial system.