Hydraulic control is a popular method for control contaminant transport through groundwater. Also, sheet piles are perfectly used for control and delaying seepage and contaminant transport through soil. Due to imperfections of sealing, corrosion, or due to accidental damage, a long horizontal slot is present in the sheet pile at depth below the ground, which allows enough water and contaminant to pass through it.
The present paper investigates the effect of defects in steel sheet pile on seepage and contaminant transport whenever the slots at various distances from the ground happened. To solve the seepage and contaminant transport through groundwater, a numerical model (Geo-Studio) based on the Finite Element Method was utilized. The current study is two-dimensional flow for the effect of slot place and sheet pile depths and other values, soil hydraulic conductivity, head difference between upstream and downstream pile, breadth of the gap, and distance between the contamination source and the sheet pile. The flux is increased in case of the sheet pile with slot than the sheet pile without slot because the velocities magnitudes have increased and flow go through the slot. It was recommended equations for calculating total seepage discharge and seepage under sheet pile with slot for known depth of slot with maximum error 5.78 % and 1.922 % respectively. Also decreases the depth of the slot from ground accelerate the contaminant transport to arrive the downstream ground through the slot. An equation for calculating the traveling time of contaminant through the slot was recommended.