Investigation was carried out on the slope stability of lateritic soil due to effects of some geotechnical properties in selected burrow pits in Akure, Ibadan, Ewekoro and Iperu areas, south western, Nigeria. The geotechnical properties were determined in accordance with American Society for Testing and Materials (ASTM) Standards. The conventional slope stability analysis was based on the linear Mohr – Coulomb failure criterion utilizing the notion of safety factors with respect to shear strength, where their average results of cohesion, angle of friction, bulk density and moisture content from the locations are 82 kPa, 18 degree, 1700 kg/m3, and 22 % respectively. The average specific gravity for locations was 2.73. The degree of permeability was very low except for location 6 in Ibadan area which is medium. The grain size distribution for the locations was classified into SC – SM (silt clayey sand). From compaction test, average moisture content, average wet density and dry density for the locations are 23 %, 1849 kg/m3 and 1512 kg/m3 respectively while the average compaction curve deduced 24 % optimum moisture contents and 1639 kg/m3maximum dry density. The Atterberg limits test results indicate that locations 1 – 5 were recorded as plastic soil while location 6 non-plastic soil. Also, the linear shrinkage degree of expansion for location 1 – 5 indicates critical while location 6 indicates non-critical. Finally, statistical mathematical model equations were developed. The factor of safety for locations 1 – 5 was satisfactory for routine extraction and loading operations while location 6 was unsafe due to loading conditions of the terrain.

Engineering geological and foundation characteristics of granite derived subsoils at Ibuji area was investigated. The rock out-crops of the area were mapped. The dominant rock in the area is granite and the area generally falls within the precambrian basement rock terrain of Nigeria. Structural features in the rocks include micro joints, veins and minor fractures. Laboratory test results of the disturbed soil samples collected showed a natural moisture content ranging from 30.06% to 35.02%, liquid limit from 40% to 55%, linear shrinkage from 8.5% to 9.4% and specific gravity from 2.60 to 2.65. The dominant subsoils are clay and sands with good foundation properties.

The research correlated physical and mechanical properties with penetration rate of drilling in some typical limestone quarries in Ogun State, Nigeria. The work was carried out using the field data and rock samples collected from the two locations [Sagamu (A) and Ewekoro (B)]. Field data were used for the determination of penetration rate while rock samples were used for the laboratory analysis. The result of modal analysis from the thin section shows that sample A has the mineralogical composition of 79.5% calcite, 13.5% quartz and 7.0% opaque while sample B has 77.5% calcite, 17.0% quartz and 5.5% opaque. The average density, porosity and rebound hardness of samples from locations A and B as determined in the laboratory are 2.68g/cm3, 3.08%, 32.3 and 2.71g/cm3, 3.06%, 35.1 respectively. The result of Uniaxial Compressive Strength (UCS) as estimated from the correlation chart between average density and Schmidt hardness shows that location A has average strength of 61.8 MPa while B has 72.4 MPa. The point load strength index for location A has an average value of 1.6 MPa and B has an average value of 1.8 MPa while the tensile strength as estimated from point load strength index for A is 2.5 MPa and B is 2.7 MPa. The penetration rate as determined from field data shows that location A has an average penetration rate of 0.7 m/min and location B has an average penetration rate of 1 m/min. Statistical model was developed using Statistical Package for Social Sciences (SPSS) software and the result shows that there is a strong correlation between penetration rate and porosity, rebound hardness value and density. The result also shows that the porosity, rebound hardness value and UCS have negative influence on penetration rate while density has positive influence on penetration rate.

The research analyzed the correlation of strength properties of limestone deposit in Ogun state, Nigeria with penetration rate using linear regression analysis for engineering applications. The research was conducted using the field data and rock samples collected from the two locations, [Sagamu (1) and Ewekoro (2)]. Field data were used for the determination of penetration rate while rock samples were used for the laboratory analysis. The average density and rebound hardness of samples from locations 1 and 2 as determined in the laboratory in order to estimate uniaxial compressive strength are 2.68g/cm3, 32.3 and 2.71g/cm3, 35.1 respectively. The result of Uniaxial Compressive Strength (UCS) as estimated from the correlation chart between average density and Schmidt hardness shows that location 1 has average strength of 61.8 MPa while location 2 has 72.4 MPa. The point load strength index for location 1 has an average value of 1.6 MPa and location2 has an average value of 1.8 MPa while the tensile strength as estimated from point load strength index for location 1 is 2.5 MPa and location 2 is 2.7 MPa. The penetration rate as determined from field data shows that location 1 has an average penetration rate of 0.7 m/min and location 2 has an average penetration rate of 1 m/min. The correlation between the strength properties and penetration rate for location 1 shows that there is a very strong relationship between penetration rate and uniaxial compressive strength, point load strength and tensile strength while location 2 shows that there is a strong relationship between penetration rate and uniaxial compressive strength and a moderate relationship between penetration rate, point load strength and tensile strength.

Estimation of strength properties (uniaxial compressive and point load) from physical properties (density, porosity and rebound hardness) of shale rock type from Kogi State, Nigeria was investigated. The shale rock types were sampled and tested for their properties through in-situ and laboratory tests conducted. Schmidt hammer was used to carry out the in-situ testing of the rock on the field while rock samples were collected for laboratory test. Four samples of each rock type were prepared for the determination of density and porosity. The results obtained from the Schmidt hammer test and those of density determined from laboratory test were used to estimate the uniaxial compressive strength of the rock. The average density and porosity of the shale are 2.39 g/cm3 and 38.4%. The average uniaxial compressive strength and point load index values are 34.20 MPa and 1.60 MPa respectively. From the results, the strength parameters indicated high strength classification. The determined physical and strength parameters were analyzed statistically. Mathematical models were derived from the relationships between the parameters for the estimation of strength properties of the rock and the coefficient of their correlation (R2) indicated strong relationship. The results obtained would be useful tools for the prediction of the strength properties of rocks having similar physical properties as the investigated rock type.

The mechanical (uniaxial compressive and tensile strengths) and petrographic properties (allochem average size, fraction quartz, dolomiteand aragonite) of two carbonate rock types in South West Nigeria has been determined. With 115 test results from the limestone and dolomitic marble samples, MINITAB 15 statistical software was used to correlate the mechanical properties to the petrographic data. Preliminary results suggest that allochem average size and the proportion of quartz may be used to correlate the data for limestone samples while the fraction of dolomite and aragonite may be used for the dolomitic marbles.

Fractures orientations analyses were carried out on two faces tagged face 1 and face 2 at dolomite deposit quarry in Ekpeshi, Nigeria. Two joint sets were identified. Kinematic analyses carried out with the aid of DIPS software show different types of failure. Face 1 of Ekpeshi quarry is susceptible to wedge failure while toppling failure is not a threat on this face. Face 2 of Ekpeshi dolomite is partly under the threat of plane failure. There is no possibility of wedge failure on this face. Also there is no threat of toppling failure on the dolomite face 2. It was observed from the analyses that little attention was paid to relationship between cut face and fracture orientation in the case study area. Although there was no tension crack which could have aggravated slope failures, however the toes of the slope were heavily flooded; this situation may reduce friction between fracture surfaces and aid sliding. It was concluded and recommended that fractures orientations analyses should always be carried out to determine the proper orientation of cut face in relation to fracture orientation. Also there should be proper drainage at the toes of the slope to prevent percolation which might reduce friction between discontinuities surfaces so as not to turn profitable mines to loss and to minimize if not prevented, failures that can be dangerous to both personnel and equipment.

Six igneous and metamorphic rock types were investigated for their petrographic, bulk density and abrasion resistant characteristics. Petrographic microscope to which a digital camera was attached, balance with necessary equipment set up for Archimedes’ principle measurement and abrasion tester were used to determine the petrographic, bulk density and abrasion resistant characteristics respectively of the rock types after various sample preparations. Generally, quartz, biotite, plagioclase, microcline and hornblendeconstitute the major minerals in the thin sections of the rock types and the microstructures that were exhibited include cleavage, distorted cleavage, mineral inclusions, micro-cracks, bent twin lamellae, mymerkite and compressed twin plane. Biotite granite has the lowest bulk density of 2.63g/cc while the charnockitic rock has the highest of 2.81g/cc. The result of abrasion resistance shows that granite gneiss and porphyritic biotite granite have very low values of 26.50 and 26.65 respectively while lamprophyre and charnockitic rock have very high values of 34.40 and 33.40 respectively. A very high correlation coefficient of 0.9179 was recorded for the relationship between the bulk density (D)and abrasion resistance (Ha)of the rock types. A model relating the two properties, Ha = 46.79D – 97.43, was derived. Conclusively, bulk density has direct relationship with the abrasion resistance of igneous and metamorphic rocks and it is therefore used to estimate it.

The inter-relationship of bulk density and porosity of some crystalline rocks in southwestern Nigeria was investigated. Six crystalline basement complex rock types from two localities in Nigeria (three each from Akure and Igarra) were sampled and tested for their petrography (mineralogy, texture and microstructures), bulk density and porosity. ImageJ was used for image analysis of the photo-micrographs, the bulk density was calculated from the determined specific gravity while the porosity was determined by water saturation technique. From the results of the analyses, the rocks were found to contain quartz, feldspar, hornblende, mica and minor minerals in various proportions. Micro-structures such as bent twin lamellae, undulose extinctions, distorted and incomplete twining and platy mineral alignment were observed in the thin sections of the rocks. The bulk density values ranged from 2.63 to 2.81 and the porosity from 0.03 to 0.16. The correlation coefficient relating the two parameters is -0.9713 indicating a very high negative correlation. The square of Pearson Product moment correlation coefficient is 0.9434. A mathematical model was derived from the relationship between the two parameters. The standard error of 0.02 and the Ftest of 0.98 were determined for the model. It was deduced that the porosity of a crystalline rock is affected mainly by its bulk density and possibly by the degree of weathering.

Evaluation of some engineering properties of granitic rock types were carried out in selected quarries in Ekiti and Ondo states, Nigeria. The Rock Quality Designations (RQD); Uniaxial Compressive Strength (UCS); and Aggregate Crushing Value (ACV) of the rocks were determined both in the laboratory and on the field using international standard procedures. Subsequently, relationships were established between the determined rock strength parameters. From the results of the investigation, the granite rocks from the study areas were quantitatively evaluated and classified into different strength categories. The RQD of the rocks varies between 65.11% and 89.19% which reveal that the rocks range between fair and good in quality. The UCS varies from 65.65 MPa to 105.38 MPa which indicate that the rocks range from medium to high strength. The ACV varies from 21.99% to 28.31%. The result showed that the higher the RQD and UCS values, the lower the ACV. It was equally established that there are strong relationships between the values of RQD, UCS and ACV. The work will serve as additional database and help in optimizing the engineering design processes involving the use of the determined rock properties before and during excavation of the rock type.