Influence of Oil Contamination on Geotechnical Properties of Basaltic Residual Soil

Abstract

<b>Problem statement:</b> Oil contamination due to accidental spillage or leakage brings hefty damage to the environments. It percolates steadily into subsurface environments and contaminates the soil and water system. Hydrocarbon contamination has not just affected the quality of the soil but will also alter the physical properties of oil-contaminated soil. <b>Approach:</b> This study presented the geotechnical properties of oil-contaminated soils as well as uncontaminated soils for comparison. Testing programs performed on the studied soils included basic properties, Atterberg limit, compaction, permeability and unconsolidated undrained triaxial tests. The base soils used were originated from weathered basaltic rock of grades V and VI. Soil samples were artificially contaminated with 4, 8, 12 and 16% oil of the dry weight of based soils. <b>Results:</b> The results showed that the oil contamination decreased the liquid limit and plastic limit values for both grades of weathered soils. For soil grade V, the decrease in plastic limit and liquid limit were represented by 21 and 39%, respectively. Meanwhile, for soil grade VI, the drop was significantly high for liquid limit (39%) and lower for plastic limit (19%) if compared to soil grade V. The oil-contaminated soils also indicated a lower Maximum Dry Density (MDD) and optimum water content if compared with uncontaminated soils. The MDD for soil grade V and VI decreased from 1.67-1.50 and 1.60-1.55 g cm^-3, respectively. The OMD values dropped from 23.5-17.5% for soil grade V and 23.0-16.5% for soil grade VI when oil contents were increased. A reduction in permeability was observed as a result of the oil contamination. The permeability of soil grade V and VI decreased from 3.74-0.22 and 2.65-0.22 cm sec^-1, respectively. In terms of undrained shear strength, C_u was clearly affected by the increase in oil content in contaminated soils. Both soil grades showed stress dependant behavior with a brittle mode of failure. The C_u values for uncontaminated soils of both grades were 126 and 106 kPa and then dropped to very close values of 35 and 32 kPa at oil content of 16%. <b>Conclusion:</b> The results showed that the addition of oil has adverse effects to the geotechnical properties of the studied residual soil. Contaminated residual soils might be used for geotechnical purposes and these results will benefit to engineers or decision makers in recycling or re-using of contaminated soils

Geotechnical properties of hydrocarbon-contaminated soils: a comprehensive review

“…It can be generally discussed herein that hydrocarbon contaminations reduces hydraulic conductivity of soils (Akinwumi et al 2014a;Akinwumi et al 2014b;Al-Sanad et al 1995;Budhu et al 1991;Cook et al 1992;Foreman and Daniel 1986;Khamehchiyan et al 2007;Meegoda and Rajapakse 1993;Puri 2000;Puri et al 1994;Rahman et al 2010;Shin and Das 2000;Siang et al 2014;Silvestri et al 1997;Singh et al 2008;Singh et al 2009;Tuncan and Pamukcu 1992;Uppot and Stephenson 1989). Totally, deposition of hydrocarbon compounds into soil pores, as influential elements governing hydraulic conductivity of soils, considerably decreases soil permeability.…”

“…One of the important characteristics of fine-grained soils contaminated by hydrocarbon compounds has been Atterberg limits. In a more general sense and based on an overall look at some relevant research (Akinwumi et al 2014a;Akinwumi et al 2014b;Alhassan and Fagge 2013;Jia et al 2010;Kermani and Ebadi 2012;Khamehchiyan et al 2007;Khosravi et al 2013;Nazir 2011;Pusadkar and Bharambe 2014;Rahman et al 2010;Solly et al 2015;Srivastava and Pandey 1998;Ukpong and Umoh 2015;Walia et al 2013), the authors are not able to find a comprehensive trend describing the effects of hydrocarbons on these limits. To elucidate this fact, the authors have approximately accumulated all the data provided in the literature regarding both LL and PI of hydrocarbon-contaminated soils in Fig.…”

“…Due to probable effects of pore fluid on soil compaction, several studies have been concentrated so far regarding compaction behaviors of hydrocarbon-contaminated soils. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 Bharambe 2014; Rahman et al 2010;Silvestri et al 1997;Srivastava and Pandey 1998;Walia et al 2013), with the exception of (Singh et al 2009), adding hydrocarbon compounds could significantly diminish OMC with 4.3% in CL (Akinwumi et al 2014a) up to 86% in poorly graded sand (SP) (Khamehchiyan et al 2007). However, (Singh et al 2009) observed that OMC of both CL and CH soil increased almost by 12 and 22%, respectively, as the amount of hydrocarbon content (used motor oil) rose to 9 (wt.%).…”

“…On the other hand, MDD experienced different hydrocarbon-induced changes. In a majority of research studies (Akinwumi et al 2014a;Akinwumi et al 2014b;Khamehchiyan et al 2007;Pusadkar and Bharambe 2014;Rahman et al 2010;Silvestri et al 1997;Singh et al 2009;Walia et al 2013), as hydrocarbon compounds increased in soils, MMD diminished accordingly. Moreover, some researchers observed that MDD increased as hydrocarbon content rose in soils.…”

Analysis on the suitability of exploiting oil-contaminated soils in wearing layer of Asphalt concrete

“…A study by Rahman, Hamzah, Taha, Ithnain, and Ahmad (2010) showed that contaminates in OCS would have lower Maximum Dry Density and optimum water content if compared with uncontaminated soils, in general, a decreased permeability and kPa. They claim that despite the adverse effects, contaminated residual might be used for geotechnical purposes.…”