Influence of Gas Oil Contamination on Geotechnical Properties of Fine and Coarse-Grained Soils

Oil contamination in soils causes several geotechnical problems that must be considered during construction. The contamination occurs due to oil seepage which could happen during oil explorations and production processes or oil transportation. The site of West Qurna oilfield in Basrah was selected for this study because it has witnessed oil seepages many times. In order to study the significant impact on geotechnical properties of soils in the West Qurna site, as uncontaminated bulk soil sample was taken at a depth of 1 m, and crude oil was added at weight ratios of 2, 4, 6, 8, and 10 %. Laboratory tests were performed on all samples; these tests included particle size distribution, moisture content, Atterberg’s limits, consolidation, unconfined compressive strength, and water absorption. The results show that soil at the West Qurna site is clayey silt with little sand and the moisture content is 29.21%. The values of liquid limit and plasticity index were gradually decreased, while the plastic limit was increased with increasing of crude oil in the soil of study. There was an increase in consolidation coefficients [compressive index, swelling index, pre-consolidation pressure, and coefficient of consolidation] with an increase in the percentages of crude oil in the soil. The results also show that there was a decrease in the values of unconfined compressive strength and absorption of water as the crude oil was increased in the soil.

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Evaluation of geotechnical properties of gully erosion materials in ORLU and its environs, IMO state, Nigeria

International Journal of Advanced Geosciences ◽

10.14419/ijag.v4i1.5991 ◽

2016 ◽

Vol 4 (1) ◽

pp. 8

Author(s):

Iheme O.K ◽

Okoye V.U. ◽

Chinwuko A.I. ◽

Usman A.O. ◽

Ejeke C.F. ◽

...

Keyword(s):

Environmental Protection Agency ◽

Geotechnical Properties ◽

Gully Erosion ◽

Geological Mapping ◽

Coarse Grained ◽

Anthropogenic Factors ◽

Rock Materials ◽

Imo State ◽

Minor Road ◽

Limit Test

The evaluation of geotechnical properties of rock materials is used to ascertain the environmental factor that necessitated gully erosion in Orlu and its environs, Imo State, Nigeria. The study is aimed at geotechnically defining the characteristics, causes and formation of the gully erosion with particular emphasis on the current land degradation in the study area. Data used in the study were derived from field measurements, and laboratory analysis. Gully variables such as length, depth and widths were also determined. The result of the geological mapping revealed that there are three geologic formations encountered in the study area namely; Ameki, Ogwashi Asaba, and Benin Formations. The result of the field studies shows that 27% of the gullies observed occur in Ameki Formation while no gully was discovered in Ogwashi Asaba formation. The grain size distribution curves interpretation revealed that 80% (by weight) of the soils are medium to coarse grained sand and fine gravels, while the remaining 18% and 2% are for fine grained sand and coarse grained silt. The Atterberg Limit Test interpretation shows that the plasticity index of the formations ranges from 24.83% to 48.42%. Based on the results of the geotechnical properties of rock materials in the study area, the factors responsible for gullies occurrence in the study area were identified as topography, rainfall, geology, and anthropogenic factors. The devastating effects of gully erosion in the study area were observed to include loss of about 22km2 of arable lands; 2 major and 6 minor road failures; loss of many houses and other infrastructures; pollution of surface and underground water. Finally, it is recommended that the appropriate authorities, individuals and all stakeholders in the environmental protection agency should develop ideas in environment watch towards gully erosion control.

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