Nature and engineering characteristics of foundation soils in Ibeju Lekki area of Lagos, southwestern Nigeria.

  • N. O. Adebisi
  • J. Osammor
  • K. F. Oyedele
Keywords: Creek, Strength, Settlement, Foundation and Subsoils


An investigation of the geotechnical properties of foundation soils was carried out in Ibeju Lekki area of Lagos, Southwestern Nigeria. This was with a view to establishing the nature and engineering characteristics of the subsoils and their behaviour under structural loading. Twenty-five (25) Standard Penetration Tests (SPT) and thirty-five (35) Cone Penetration Tests (CPT) were carried out while thirty-three (33) soil samples were collected. In-situ test parameters (cone resistance and SPT number of blows), index properties (natural moisture content, grain-size distribution and consistency limits), shear strength parameters, compressibility properties, Califonia Bearing Ratio (CBR) and moisture-density relationship were determined in compliance with specifications of the British Standards (BS) 5930, 8004 and 1337. The subsoils in the shallow groundwater level area, were a combination of soil types (clay-sized particles = 9 – 12 % , silt -sized particle= 2 - 9 %, sand = 62 - 87 %, gravel = 2 – 28 %), variable consistency (L = 43 - 118% and I = 19 – 69 %) and shear L P 2 0 strength parameters (C = 20 – 100 kN/m and = 1 - 9 ). For shallow foundation within 1.0 m and 2.0 m, a total u 2 settlement of 23.65 mm was estimated to occur under assumed loading intensity of 45 kN/m with allowable 2 bearing capacity of 121 kN/m . For deep foundation, the allowable loading bearing capacity for a pile of 600 mm diameter set at 8.0 m would be 940 kN. CBR and compacted density results indicated a sub base thickness range of 100 mm - 150 mm for a proposed road layer compacted at optimum moisture content to take care of probable groundwater fluctuation in the area.

Keywords: Creek, Strength, Settlement, Foundation and Subsoils


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eISSN: 0794-4896