DEPENDENCE OF SHEAR STRENGTH AND COMPRESSIBILITY OF TROPICAL LATERITIC SOILS ON CLAY CONTENT. ARTICLE IN: International Journal of Engineering and Technology Research (original) (raw)
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International Journal of GEOMATE, 2021
Residual shear strength plays a very significant role in geotechnical engineering. This concept has contributed extensively to diverse studies on soil behaviors under the influence of shear failure, both in drained and saturated conditions. In terms of landslides, the assessment of the residual shear strength after an occurrence and the progressive failure risk of slope stability has been very useful. However, information on this shear property in laterite soil appears relatively minimal. This soil type is the most frequently applied embankment for road construction in every Kalimantan region. Therefore, the purpose of this research is to determine the behavior of residual shear strength in laterite soil and the effects of adding coarse sand and clay fractions, using direct shear analysis. Subsequently, the specimens were prepared by compaction tests to obtain the optimum moisture content and uniform density, using coarse sand of varying proportions, termed 5, 10, 15, 20 and 25%, while, the shear strength treatment with wetting and drying cycle conditions was conducted under 2, 4, 6, 8 and 10 days, respectively. The results showed that the addition of the coarse sand and clay (CL) portions was able to increase the residual shear strength parameters (cohesion and internal friction angle) by 4-6%, compared to the pure state. Therefore, the introduction of clay (CL) materials ranging from 20-25% appears suitable in enhancing the residual shear strength of laterite soil. However, the extensive wetting-drying cycle tends to reduce the peak and residual shear strength.
Important Properties of Clay Content of Lateritic Soils for Engineering Project
Journal of Geography and Geology, 2013
Clay-sized particles have been shown to control the engineering performance of lateritic soils, while the mode of formation and mineralogical composition of parent rocks in evaluating properties peculiar to clay-sized particles are yet to be a subject of serious research. Fresh Gneiss (GN), Quartz-schist (QS) and Granite (GR) were sampled in parts of Southwestern Nigeria. Thirty samples each of disturbed and undisturbed soils were also obtained at depths of 1.0, 1.5, 2.0, 2.5 and 3.0 m from profiles over GN, QS and GR. X-ray fluorescence and X-ray diffraction were employed to determine the major oxide geochemistry and clay mineralogy respectively, while grain-size distribution, plasticity characteristics, undrained cohesion (Cu) and volume compressibility (Mv) were determined following the British Standards (BS-1337).
Nigerian Mining Journal, 9(1), 7-17., 2011
The geotechnical properties of Lateritic soils from part of Jos and environs have been investigated covering 78km2 within latitudes 80 50` to 80 56` N and Longitude 90 50`to 09 0 54`E, central Nigeria; with a view to assessing the suitability of the soils for construction and other engineering applications. Representative samples were collected from twenty locations within the study area and subjected to series of laboratory geotechnical analyses such as the grain size analysis, Atterberg limits, Liquid/Plastic Limit tests, Plasticity Index, Linear Shrinkage Tests, Compaction and shear Strength tests in Accordance with procedures of the British standard (BS)1377 with necessary modifications. Geotechnical results obtained revealed that the liquid limit ranging from 30.3 – 61.7 % and plastic limit ranged from 22.5% - 40.6%. The plasticity index was found to be between 7.8% and 21.7% and linear shrinkage values ranged between 5.7 and 11.4 indicating low – medium swelling potential with some indication of expansiveness by some of the samples. Based on the Unified Soils Classification System (USCS), the soils of the study area can therefore be poor, fair or good materials. Based on compaction characteristics the soils can be considered poor to fair and therefore suitable for construction of embankments. Some of the soils will require some form of improvement in order to be suitable for highway construction and other applications. From the established coefficients and angles of friction of soils derived from the Morh’s circle of the study areas, the various bearing capacities of soils can also be determined for civil and construction purposes.
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.
Variability in the Geotechnical properties of some residual clay soils from southwestern Nigeria
Some residual clay soils from southwestern Nigeria have been investigated with a view to elucidating their geotechnical properties and determine the possible variations in these properties in relation to the sampling distance. Eight bulk residual soil samples from two test pits separated 30m apart at intervals of 0.5m up to a depth of 2.0m were analyzed in the laboratory to determine specific gravity, grain size distribution, consistency limits, linear shrinkage, unconfined compressive strength and compaction characteristics. The data generated were subsequently subjected to statistical analysis. The investigations revealed that the soils are generally well graded, inorganic, with medium to high plasticity and hence compressibility and are of the same geologic origin. Statistical T-test showed no significant difference exists between the soils in terms of specific gravity, liquid limit, plastic limit, plasticity index, linear shrinkage, % clay size fraction, amount of fines, unconfined compressive strength and optimum moisture content. However the maximum dry density of the soils from both pits differed significantly. Although most of the parameters examined are not as varied and showed insignificant difference, the equations generated provide an option in the estimation of properties considering the close sampling distance.
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
AN INVESTIGATION INTO THE GEOTECHNICAL ENGINEERING PROPERTIES OF LATERITE SOILS IN NILAI, MALAYSIA
An increase in construction and material use in tropical environments has made way for engineering knowledge of related basic properties of soils within those areas. One such soil found abundantly are the laterite soils. This study is based on determining the engineering geotechnical properties of laterite soils which are observed to occur in the town of Nilai, Malaysia. These basic properties were generally determined for non-problematic laterite soils.
Geotechnical Properties of Clay Soilsin Uyo Town, Eastern Niger Delta, Nigeria.
IOSR Journals , 2019
This study investigates, the geotechnical and mineralogical properties of clay soils in Uyo town, for construction purposes. On the basis of the field and laboratory investigations, the general subsurface profile of Uyo town consists of silty clays from 0-3m, sandy clays (3-15m) and sand from 10-20m.The silty clays are firm with a low to intermediate plasticity and high cohesion values, while the sandy clays, are also of low to intermediate plasticity, with high consolidation and cohesion values, that are expected to yield relatively higher shear strength than the silty clays. X-raydifraction analysis of the clays reveal the presence of kaolinite, quartz and trace amounts of goethite in the silty clays. Analysis of the foundation potentials using CPT results show that the silty clays have low potentials while the underlying sandy clay horizon may be suitable for small and medium civil engineering structures.
Nigerian Journal of Technology, 2017
The compaction and consolidation characteristics of lateritic soils in Ikole area of Ekiti State were investigated. The investigation was carried out through laboratory tests on disturbed and undisturbed soil samples obtained from three borings (BH1, BH2, and BH3) of Holy Apostolic Nursery/Primary School, Ootunja, Ikole Local Government Area (L.G.A.) of Ekiti State Southwest, Nigeria. The soils are all lateritic and mostly fine-grained. Compaction tests indicate maximum dry densities of 2.05Mgm-3 , 1.78Mgm-3 , and 1.69Mgm-3 at optimum moisture contents of 14.3%, 20.7% and 19.6% for soil samples obtained from BH1, BH2 and BH3 respectively. Compression indices (Cc) obtained from oedometer tests are 0.04816, 0.03820 and 0.04318 while the calculated coefficients of volume compressibility (mv), are 1.308*10-4 , 1.065*10-4 and 1.093*10-4 m 2 kN-1 for samples in BH1, BH2 and BH3 respectively. The unsoaked California Bearing Ratio (CBR) value at 2.5 mm penetration ranges from 42.10% to 92.40% and CBR value at 5.0 mm penetration ranges from 52.70 to 89.10% indicative of good materials for road subgrade, sub-base and base courses.