Performance of Raft Foundation under Static Vertical Loading in Contaminated Soil

Abstract

This study focuses on studying the impacts of residues oil on the geotechnical properties of soil and the performance of raft footing rested on oil contaminated soil and subjected to vertical loads. The contaminant used in the present study is residues oil, which is by product disposed of diesel engine oils. The soil samples are contaminated artificially by soaking with two percentage of disposed engine oil of contaminant consist of (disposed engine oil and gasoline) of 20% weight of dried of intact soil samples to obtain different concentrations of contaminant absorbed by soil samples for 30 days to complete the saturation. The mechanical model manufactured to investigate the behavior of raft footing under vertical static loading rested on intact and contaminated soils. The obtained results detected contaminant content have notable impacts on the physical soil characteristics such as the fine particles, specific gravity, plasticity index, and maximum dry unit weight decreased with the increase of contaminant content than that of intact soil. The mechanical soil properties of soil indicated the increase of the compressibility of soil with increase of residues oil percentage, but the soil strength and stiffness are decreased notably. In addition, the total and permanent settlement of raft footing constructed in contaminated soil samples increased by (27-43) % and by (41-58) % than that of an intact soil sample, respectively.