Behavior of Pile Group Subjected to Cyclic Lateral Loading in Contaminated Soils

Abstract

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 AlMusayib 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.

Ultimate Lateral Load Capacity of Piles in Soils Contaminated with Industrial Wastewater

“…The proposed model simulates the degradation of soil strength resulting from the contamination. The results of two-line slopes and proposed degradation model are verified by experimental results presented by Karkush and Abdul Kareem [9,10].…”

“…The results were obtained at the 100th cycle of lateral loading. The soil properties and results of experimental work are obtained from Karkush and Abdul Kareem [9]. The results showed good agreement between the maximum lateral load-bearing capacity obtained by TLSI and Equation 2.…”

“…Also, two ratios of eccentricity to length (e/L = 0.25 and 0.5) have been studied. The geotechnical properties of soil samples, the details and specifications of the physical model, dimension and material properties of the pile model are given in Karkush and Abdul Kareem [9]. The physical model used in the test of ultimate carrying capacity of pile foundation subjected to lateral cyclic loading is shown in Figure 1.…”

“…The responses of a large-diameter single pile under one-way force of cyclical lateral loads was studied by Li et al [8], they investigated the accumulated lateral permeant displacements and the pile's lateral secant stiffness. Karkush and Abdul Kareem [9] studied through experiments, the effects of lateral cyclical loading on the behavior of a single pile driven into clayey soil contaminated with 4 ratios of industrial wastewater. The results of study showed significant effects of contamination on the maximum lateral capacity and total and permanent lateral displacements of pile.…”

“…The results of study showed significant effects of contamination on the maximum lateral capacity and total and permanent lateral displacements of pile. Also, Karkush and Abdul Kareem [10] studied, through experiments, the effects of lateral cyclic loading on the behavior of piles group driven into intact and contaminated clayey soil with 4 ratios of industrial wastewater. The results of this study confirm the important of soil contamination on the ultimate lateral carrying capacity and total and permanent lateral displacements of piles group.…”