Geotechnical Characterization of Lateritic Soils in Jos and Environs North Central Nigeria By Lar, U. A., Wazoh, H.N., Mallo, S.J. & Chup, A.S. Department of Geology and Mining, University of Jos, Nigeria,(2011) Nigerian Mining Journal, 9(1), 7-17 (original) (raw)
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Laterite is a highly weathered material, rich in secondary oxides of iron, aluminum, or both. Geotechnical investigation is one of the effective means of detecting and solving pre, syn and post constructional problems. The geotechnical properties of lateritic soils and their suitability for road construction have been evaluated for selected sites in Minna, North-central Nigeria. All analyses were carried out in accordance with the British Standard Institution. The liquid limit ranged from 22.5% to 49.6% with an average value of 34.9%, plastic limits varied from 13.8% to 28% with a mean value of 21.38% while plastic index is of the order of 8.7% to 21.6% with an average value of 13.5%. The maximum dry density ranged from 1.78 g/cm 3 to 2.33 g/cm 3 with a mean value of 1.858 g/cm 3 while the optimum moisture content varied from 6.30% to 14.3% with an average value of 9.74%. The evaluation reveals that the lateritic soils have higher plastic limits, Maximum Dry Densities (MDD) and California Bearing Ratios (CBR) while their liquid limits, plasticity indices and Optimum Moisture Contents (OMC) are lower. The lateritic soils were classified as A-3, A-2-4 and A-2-6 and are adjudged suitable for sub-grade, good fill and sub-base and base materials. This geotechnical information obtained will serve as base-line information for future road foundation design and construction in the study area.
Comparison of the Geotechnical Properties of Lateritic Soils in Port Harcourt, Nigeria
This present study x-rayed the geotechnical properties of lateritic soils and their suitability as subsoil (subgrade and subbase) materials for road construction and other civil engineering works. Lateritic soil samples were collected from ten different locations in the Port Harcourt metropolis using the hand auger apparatus as the sampling tool at about 1 meter depth. The soil samples were subjected to geotechnical investigation. Results obtained from the test showed that liquid limit (LL) ranges from 32.3% to 38.6%, the plastic limit (PL) ranges from 17.6% to 21.9%, while the plasticity index (PI) is between 13.6% and 20%. The optimum moisture content ranges from 13% to 18.5%, while the results of the maximum dry density of S1 to S10 ranges from 1340kN/m 3 to 1750kN/m 3. Shear stress of the samples fall within 19.64-22.86N/mm 2 with an average of 20.76 N/mm 2. The result of all samples showed that the percentage of clay ranges from 16%-32%. The test results also revealed that the lateritic soil samples are suitable for subgrade for road pavement construction but would require adequatecompaction and stabilization to be used for subbase and base course in road pavement construction and other civil engineering works.
Major components of several typical flexible highway pavements are; sub-grade, sub-base, base-course and riding surfaces from the base to the top (Adeyemi, 2013; Gupta and Gupta 2003). Causes of road failure around Nepa and its Environs is due to the presence of deformation such as; potholes, cracks, depression and ruts. Other factors may be due to geological, geomorphological, geotechnical, poor design, construction inadequacies and maintenances. Lateritic soils are also used as a foundation material for other engineering structures like; airfield, low-cost housing and compacted fill in earth embankments (Abubakar, 2006; Kamatchueng et al., 2016; Oke and Amadi, 2008). The mineralogical composition of lateritic soil has an effect on the geotechnical parameters such as; Atterberg limits, Specific gravity, Shear strength, Swelling potential, Bearing capacity and Petrographic properties (Amadi et al., 2012). The work of several authors like (
NIGERIAN ANNALS OF PURE AND APPLIED SCIENCES, 2020
Due to failures of Civil Engineering structures in Jos and its Environs, Geotechnical parameters of Lateritic soils were carried out in order to determine its engineering properties for civil engineering construction. The methods involved are; reconnaissance survey, site works, laboratory tests based on British Standard (BS) methods and interpretation of the results. The laboratory test of the soils revealed that the Atterberg limit; Liquid limit (LL) ranged from 33.0% to 45.0%, Plastic limit (PL) from 16.23% to 26.37%, and Plasticity index (PI) from 8.63% to 22.67%. The percentage passing from the Sieve analysis ranges from 31.62% to 67.66%. The cohesive strength (c) and angle of internal friction (ø) from direct shear test ranged from 13KN/m2 to 24KN/m2 and 9° to 26°. The values of the Total settlement (Pc) from the Consolidation test ranged from 0.0005m to 0.0019m, Soil pH from 5.2 to 7.8, Specific gravity (SG) from 2.57 to 2.73 and Natural Moisture Content (NMC) from 8.18% to 46...
Geotechnical Properties of Lateritic Soils from Northern Zone of Anambra State, Nigeria
This investigation was carried out to determine the geotechnical properties of lateritic soils used for road construction in Obosi, Umunya, Awkuzu, and Igbariam towns, all in Northern Zone of Anambra state of Nigeria. Tests were carried out on the soil samples which include the Atterberg limit tests, particle size distribution analysis, specific gravity, compaction test using the British Standard Light (BSL), Compactive effort and California Bearing Ratio (CBR) test as specified by the West African Standard (WAS). The liquid limits, plastic limits and plasticity indices guided in the classification of the soil samples as A-2-4 soil of American Association of State Highways and Transportation Officials (AASHTO) classification and SC group of Unified Soil Classification System (USCS). The compaction characteristics of the soil were found to be 1931KN/m3, 2003.8KN/m3, 1965KN/m3 and 1923KN/m3 for maximum dry density and 10.8%, 9.4%, 10.4% and 12.20% for optimum moisture content for samples 1, 2, 3 and 4 respectively. The California bearing ratio (CBR) results for the samples for 24 hours soaking are 48%, 58%, 45%, and 52% for sample 1, 2, 3, and 4 respectively. It was concluded that the four lateritic soil samples were suitable for sub-grade and sub-base but should not be used in road construction as a base material.
Engineering Properties of Lateritic Soil in Otun Area, Ekiti State, Nigeria
African Journal of Engineering and Environment Research, Volume 2 of 1, January, 2021
Lateritic soils at Otun Ekiti, Ekiti state, southwestern Nigeria were investigated with respect to their geotechnical properties and their suitability for subgrade and subbase construction materials. Four disturbed lateritic soil samples (sample A, B, C and D) were selected for the various laboratory techniques. The grain size analyses, the specific gravity tests, the atterberg limit tests, compaction, California bearing ratio and shear box tests were carried out on the samples. The grain size analysis shows that sample A is gravelly silt-clayey sand. Sample B is siltclayey gravel composition. Sample C is gravelly silt-clayey while Sample D is silt-clayey gravel. Atterberg consistency limit test indicate that sample A has 30.0%, liquid limit 19.5% plastic limit, 10.5% plasticity index, 9.1% shrinkage limit. Sample B has liquid limit of 27.0%, 16.2% plastic limit, 10.8% plasticity index and 7.4% shrinkage limit. Sample C has a liquid limit of 32.4%, plastic limit of 15.6%. It has a plastic index of 16.8%, Shrinkage limit of 9.7% while Sample D has a liquid limit of 36.2%, plastic limit of 17.7%. It has a plastic index of 18.5% and 11.1% as shrinkage limit. Thus, the soil is classified to be intermediate plasticity which can be used for subgrade and subbase materials. The soil samples are above the activity (A) line in the zone of intermediate plasticity (CL) which suggests that they are inorganic soils. Based on engineering use chart, the workability as construction engineering is good to fair particularly as erosion resistance in canal construction. However, the high shrinkage limit may also reduce erosion in this area because of cohesion of the plastic clay material. The California Bearing Ratio (CBR) values are within 2-3% (mean = 2.75%) and 2-4% (mean = 2.75%) in sample A and sample B respectively while California Bearing Ratio (CBR) of 2-4% (mean = 2.75%) and 2-3% (mean = 2.75%) in sample C and sample D respectively. This implies that the materials can be used as a sub-grade to base course material for support of flexible pavements. The compaction tests for the optimum water content for sample A is 15.0% and 13.0% for standard and modified proctor respectively. The standard and modified proctor
This present work was carried out to determine the geotechnical properties of Olokoro lateritic soil. Tests were carried out on the sample soil which includes the Atterberg limit tests, particle size distribution analysis; sedimentation test, compaction test using the West African standard and California Bearing Ratio (CBR) test as specified by the Nigerian General specification (1997). The liquid limit, plastic limit and plasticity index were found to fall into A-2-7 soil of AASTO classification and SP group of Unified Classification. The compaction characteristics of the soil were found to be 1.90mg/m 3 and 14.76% for maximum dry density and optimum moisture content respectively on West African Standard. The CBR value was found to be 26%. It was recommended that the soil is good as a filling material in road subgrade and other construction works and require modification to improve its properties for sub-base and road base material.
Investigation of the geotechnical conditions of the Sub-soils around Yelwa North Central part of Nigeria was carried out in order to know the possible causes of the infrastructural failures in the area. The investigation involves in-situ collection of the disturbed and undisturbed soil samples and were analysed in the laboratory based on British Standard (BS) method for soil testing for civil engineers. Results of the study reveals that; The Atterberg limit (Liquid limit ranged from 33.0% to 43.0%, Plastic limits from 16.23% to 26.37%, Linear shrinkage from 7.86% to 15.71%, Plasticity index from 7.63% to 24.77%). The Sieve analysis shows that; the percentage passing of the soil samples ranges from 31.62% to 67.60% which indicates poor materials. The Direct shear test revealed that the cohesive strength (c) ranges from 13 kN/m 2 to 24 kN/m 2 , angle of internal friction (ø)° from 12° to 16° and unit weight (ϒ) from 18.17 kN/m 3 to 20.87 kN/m 3. From the Consolidation test; the Total settlement (Pc) ranges from 0.0008 m to 0.013 m, Coefficient of Consolidation (Cv) from 87.657 m 2 /yr to 109.325 m 2 /yr and Volume Compressibility (Mv) from 0.0048 kN/m 2 to 0.0205 kN/m 2. The Soil pH ranges from 6.4 to 7.4, Specific gravity (SG) from 2.57 to 2.73, and Natural Moisture Content (NMC) from 8.48% to 25.77%. The Compaction test revealed that; the Optimum Moisture Content (OMC) ranged from 13.22% to 20.60%, Maximum Dry Density (MDD) from 1.59 g/cm 3 to 1.88 g/cm 3 which shows that the soil are mostly of silty-clay material and Un-soaked value of California Bearing Ratio (CBR) ranges from 50.88% to 96.51%. The findings have revealed that, the subsoil is characteristically fair to poor, and this required a form of geotechnics. Information acquired from the findings are expected to serve as guide in the choice of design and construction and as a baseline subsurface soil compendium for the construction of infrastructure in the study area and for further studies.
SN Applied Sciences, 2019
The impact of roads on the socioeconomic development and progress of any country cannot be quantified. A geotechnical investigation of subsoils along Isinbode-Ara road, stretching in southeastern to northwestern direction of 7 km distance within Ekiti State, Southwestern Nigeria, was carried out. This investigation follows the British Standard Institution, such as moisture content, particle size distribution, specific gravity, Atterberg limit, compaction, consolidation and California bearing ratio. Results of investigation showed that the moisture content, specific gravity, liquid limit, plastic limits and plasticity index ranged from 7.2-25.9%; 2.64-2.77; 24.0-61.1%; 19.2-26.2% to 4.35-38.90%, respectively. Grain size distribution showed the fine and coarser fractions range from 13.0-66.5% to 32.6-84.8%, respectively. The maximum dry density and its optimum moisture content ranged from 1.48-2.07 g/cm 3 to 11.3-30.3%, respectively. Soaked CBR results ranged from 3 to 44%. Two classes of subsoils, namely A-2-4 and A-2-6 (granular materials) and A-6 and A-7-6 (clayey soils), were identified and rendered suitable and unsuitable road construction materials, respectively. This investigation revealed that the subsoils are poor road construction materials due to its fine fractions and plasticities, which should be put into consideration during its foundation design and construction stages.
Engineering properties of the Soils around Aba, South East Nigeria
Engineering properties of the soils around Aba and its environs were investigated. Fifty four (54) bulk samples were taken from test pits dug to a minimum depth of 1.5 metres for Atterberg Limits Test, Grain Size Distribution analysis, Compaction, and California Bearing Ratio determination. Twelve (12) shell and auger boreholes were drilled to 10m using the Pilcon Wayfarer 1500 percussion rig and undisturbed samples were collected in Shelby tubes at selected intervals of 1.5 metre for Triaxial Compression Test, Consolidation test and Grain Size Distribution analysis. Twelve (12) Dutch Cone Penetrometer Sounding Tests were carried out at 10 metres depth or to refusal. The resistance of the soil was measured by means of a dial gauge attachment to the penetrometer machine. The soils classify as very fine sands, silty to clayey fine sands, or clayey silts with slight plasticity (ML), and gravelly clays, sandy and silty clays (CL) according to the Unified Soils Classification scheme (USC). Their bulk density ranged from 1.95Mg/m3 to 2.19 Mg/m3 and Natural Moisture Content varied from 12% to 21%. Cohesion values ranged from 28kN/m2 to 60kN/m2. The Maximum Dry Density (MDD) ranged between 1.09Mg/m3 to 2.17Mg/m3 while the Optimum Moisture Content (OMC) ranges from 9.5% to 19.8%. California Bearing Ratio (CBR) soaked ranged from 5.1% to 11.2% while unsoaked CBR ranged from 7.6% to 18.9%. For design of strip/square footing 1.5metres wide founded at 1.5metres depth, the average allowable bearing capacity of the soils is 25kN/m2 from cone, while the sleeve gives 50kN/m2, allowing maximum differential settlement of 25mm (1 inch), using a factor of safety of 3. For the same footing, under same conditions, the average allowable bearing capacity from SPT was 125 kN/m2 while 279kN/m2 was computed from the Undrained Triaxial Compression Test. Therefore, it is recommended that the Dutch Cone Penetration Test average bearing capacity of 25kN/m2 be used for design. Generally, the soils around Aba are compressible, friable, very loose, to loose, and are suitable as embankment material for road pavements. They are however, unsuited for use in construction of water reservoirs like earth dams and leeves due to their moderate permeability characteristics. They are excavatable in stripping operations.