Effect of oil-contamination on behavior of geocell-reinforced soil abutment wall

Oil-contaminated soil should be remediated or can be used as filling materials .The evaluation of bearing capacity of geocell-reinforced soil abutment wall is the purpose of present study under conditions of the backfill contaminated soil through numerical modeling based on PLAXIS 2D. The behavior of the wall is studied based on changes in the amount of oil, the distance between the strip footing and the wall facing (D), the height (hg) the length (L) and the number of geocell layers as well as the wall slope. The numerical results showed that the maximum length geocell layer required is 2.16 times the footing width and the optimum geocell length is equal to 1.0 times the wall height (H). The increase in the geocell height and number of geocell layers leads to increase in the soil stiffness, leading to increase in the bearing capacity of footing and decrease in the horizontal displacement of wall. The results showed that reducing the slope of the wall is very effective in reducing the horizontal displacement of the wall. In general, the soil contamination due to the oil has a negative effect on wall performance. In other words, an increase in the amount of oil reduces the percentage improvement in the wall behavior due to an increase in the height, length and the number of geocell layers. For example at hg/B = 0.6 and settlement equal to 10% of the footing width, the bearing capacity of footing for soil contamination with 9% oil reduces by 35%.