BEHAVIOR OF PILE GROUP SUBJECTED TO CYCLIC LATERAL LOADING IN CONTAMINATED SOILS

Abstract

The impact of soil contamination on the behavior of a pile group driven into clayey soils is the subject of this study. A mechanical model had been manufactured to study the behavior of pile group (2×2) subjected to one-way cyclic lateral loading, and embedded in contaminated soils. The tests were performed on a free headed pile group with two ratios of eccentricity to embedded length (e/L) equal to 0.25 and 0.5. The intact soil samples were obtained from Al- Musayib city in the center of Iraq, while the industrial wastewater is a byproduct discharged from Al-Musayib thermal electric power plant, which is located in the same region where the soil samples have been obtained. The intact clayey soil samples were contaminated synthetically with four percentages of (10, 20, 40 and 100) % by weight of distilled water used in the soaking process of soil samples, which continued for 30 days. On the basis of the results of tests, the different percentages of contaminants have nonlinear effects on the lateral load-displacement relation of the pile group. The lateral resistance of pile group decreased with increasing the concentration of contamination in the soil. The lateral bearing capacity of pile group decreased by (4-31)% for e/L equals 0.25 and 0.5, and the ratio of permanent displacement to the total displacement increased by (18-33)% with increasing the percentage of contamination in the soil. The efficiency of the pile group was (81-87)% from one single pile group.