LONGDOM Publishing

 Journal

 Empirical Relationship Between Gravimetric And Mechanical Properties Of Basement Rocks In Ado-Ekiti, Southwestern Nigeria.

 Ajayi CA, Akintorinwa OJ And Ademilua LO

 2020

In this research paper, gravimetric and mechanical parameters of Basement rocks in Ado-Ekiti, South-western Nigeria were correlated with the aim of establishing an empirical relationship between the two parameters. Fresh rock samples were taken from thirty (30) locations cutting across the geology of the study area. Simple pendulum principle and Archimedes’ principles were employed to determine the gravity and the specific gravity of the rock respectively. The mechanical parameters (uniaxial compressive strength, shear strength, Young’s modulus, Bulk modulus and Poisson’s ratio) for the thirty rock samples were determined. The cross plots of the mechanical parameters with gravity and specific gravity showed good correlation with coefficient of correlation (R) ranging from 0.52 to 0.84 and 0.52 to 0.81 respectively. The established relationship between the gravimetric and the mechanical parameters revealed that; the mechanical strength of rock is a function of the gravitational pull effect on the rocks. 

 Elsevier

 Journal

 Hydrogeophysical And Aquifer Vulnerability Zonation Of A Typical Basement Complex Terrain: A Case Study Of Odode Idanre Southwestern Nigeria

 Akintorinwa O. J., Atitebi M. O. And Akinlalu A. A.

 2020

An approach engaging Vertical Electrical Sounding (VES) and remote sensing data was carried out with a view to developing groundwater potential and aquifer vulnerability maps of the study area. One hundred and one (101) depth sounding data were acquired using Schlumberger array, with half maximum current electrode separation (AB/2) of 100 m. The VES were quantitatively interpreted using partial curve matching and computer aided iteration to determine the geoelectrical parameters of each station. The remote sensing data were processed using the application of Geographic Information System-based multi-criteria technique ArcGIS software. Eight (8) parameters namely lineament density, drainage density, slope, transmissivity, hydraulic conductivity, coefficient of anisotropy, aquifer thickness and resistivity were used to produce the groundwater potential model while five (5) parameters namely, lineament density, slope, longitudinal conductance, hydraulic conductivity and thickness of layer overlying the delineated aquifer were also used to produce the vulnerability model. The final output of overlay parameters for estimating the groundwater potential gave an index that ranged from 1-5. The zone categorised as low groundwater potential covered about 80% of the area. The majority of the area falls within low (about 80%) vulnerability and low groundwater potential rating while being relatively protected from potential contaminants infiltrating from the surface. The prediction accuracy of the groundwater potential model was established via existing hand-dug well correlation analysis. 

 ENGG Journals Publication

 Journal

 DEVELOPMENT OF DRASTICLYS MODEL FOR GROUNDWATER VULNERABILITY ASSESSMENT IN THE AKURE METROPOLIS.

 O.O. OMOTOLA, M.I., OLADAPO, O.J AKINTORINWA And K. A. Mogaji

 2020

The need for developing a novel vulnerability modeling method with the view to enhance groundwater resources sustainability management within Akure metropolis is conceptualized in this study. The proposed vulnerability modeling technique christened as “DRASTICLYS” is a modified version of the renowned DRASTIC model. Database consisting of different data sources comprising of geophysical, remote sensing, well inventory, weather, inventory of borehole and geochemical data were utilized in developing the model. Extracted from the created database were the derived pollution potential conditioning parameters (PPCPs) namely: depth to water table (D), net recharge (R), aquifer media (A), soil media (S), topography (T), impact of vadose zone (I), hydraulic conductivity (C), lineament density (L), borehole yield (Y), and longitudinal conductance (S). Two hundred and seventy nine (279) VES data employed for the study wereobtained fourteen (14) curve types with the H curve type predominant among them. The produced PPCPs themes were weighted and ranked using the mechanism of Analytical Hierarchy Process (AHP) technique under Multi Criteria Decision Analysis (MCDA). The DRASTICLYS groundwater vulnerability prediction model (DGVPM) map segmented the groundwater zones in the study into zones of no vulnerability, very low vulnerability, low vulnerability, moderate vulnerability and high vulnerability. The result of the validation conducted using water chemistry analysis showed 95% prediction accuracy and statistical analysis applied on the water samples established 78% correlation with the modelled map 

 Springer Berlin Heidelberg

 Journal

 Combine Electrical Resistivity Method And Multi-criteria GIS-based Modeling For Landfill Site Selection In The Southwestern Nigeria,

 Akintorinwa, O.J. And Okoro, O.V.

 2019

An integration of remote sensing and geophysical data was carried out in Odode-Idanre using Geographic Information System (GIS) approach with the aim of developing a landfill site selection map of the area. The area falls within the Precambrian Basement complex of southwestern Nigeria. The remote sensing involved the processing and interpretation of Landsat-7 EMT + image covering the study area and the data were used to produce the lineament, slope, drainage and land use maps of the area. The geophysical investigation involved the vertical electrical sounding (VES) technique using Schlumberger configuration with half electrode spacing (AB/2) varying from 1 to 65 m, One hundred and one (101) soundings stations were occupied within the study area. The interpretation of the VES data was used to generate the geoelectric section and determine Dar Zarrouk parameters. The results were used to generate thematic overburden and the coefficient of anisotropy maps. The geoelectric sections generally identified four geologic/geoelectric sequences that comprise topsoil, weathered layer, fractured Basement and fresh Basement. The depth to the Basement is generally less than 10 m. The multi-criteria evaluation (MCE) analysis were used to assign weights to slope, land use, drainage density, lineament density, coefficient of anisotropy and overburden thickness using the analytical hierarchy process (AHP) and this was used to produce the landfill suitability map. The area was classified into unsuitable, moderately suitable and suitable zones. The unsuitable areas cover about 21.9%, moderately suitable areas cover about 55% and the suitable areas cover about 23.1%. The suitable areas are scattered and discontinuous but predominant within the southern part of the area. For the development of waste dump site within the study area, it should be located within the southern part which was found to be suitable. 

 International Organization Of Scientific Research (IOSR Journal)

 Journal

 Relationship Between Magnetic Susceptibility And Gravity Of Basement Rocks In Southwestern Nigeria

 Ajayi C. A., Akintorinwa O. J., Ademilua O. L., Adeoye A. S.

 2019

Geophysical properties of Basement rocks within and around parts of Ado-Ekiti, Ekiti-State, South- Western Nigeria were correlated with the aim of establishing empirical relationship between the two properties. The principal Basement rocks in the study area are; Charnockite, Migmatite, Granite Gneiss and Quartzite. Fresh rock samples were taken from thirty (30) locations cutting across the geology of the study area. A total of three hundred (300) Magnetic Susceptibility measurements were obtained from the established locations. Simple pendulum principle and Archimede’s principle were employed to determine the gravity and the specific gravity repectively. The results were presented as Maps, Tables and Cross plots. The magnetic susceptibility (MS), gravity and specific gravity values range from 2.113 X 10-4 to 9.305 X 10-4, 935055.46 mGal to 1038167.647 mGal and 2.61 to 2.83 respectively. The crossplots of the magnetic susceptibility and gravity shows good correlation with coefficient of correlation (R) ranging of 85%. The established relationship between the two geophysical parameters reveals that the potential fields is a function of both the gravitational and magnetic fields existing in the rocks as a result of the content Fe-bearing minerals present in the rock. This further proves that the magnetic susceptibility of a rock can be determined by estimation from the gravity readings. Hence the established equations can be used to evaluate rock potential field parameter using either of the two measured geophysical parameters. 

 School Of Earth And Mineral Sciences, Federal University Of Technology, Akure Nigeria

 Journal

 Empirical Relationship Between Seismic Refraction Derived Velocities And Subsurface Mechanical Properties For Foundation Studies In Typical Basement

 Akintorinwa O. J. And Okunniga B. S.

 2019

The Seismic refraction derived velocities and mechanical properties datasets from the depth range from 2 to 4 m were obtained with the aim of establishing an empirical relationship between the two dataset. The Seismic refraction data were acquired at fourteen (14) profiles along five (5) traverses across. End – on shot array was adopted with station interval of 5 m. The mechanical properties datasets analyses were carried out on ten (10) soil samples taken from the depth within the first layer (2 m) delineated from seismic refraction interpretation. Two (2) soil samples were taken along each traverse where seismic refraction derived velocity values were determined. The geotechnical tests conducted include Optimum Moisture Content (OMC), Maximum Dry Density (MDD) and the California Bearing Ratio (CBR). The seismic refraction derived velocity range from 714 to 2000 m/s and the thicknesses of the first layer range from 2 to 4 m. The regression plot of seismic refraction derived velocity and the mechanical properties trend line was used to establish an empirical equation between them. From the crossplots, it was observed that Maximum Dry Density (MDD) and California Bearing Ratio (CBR) exhibit a direct relationship with the velocity, while the Optimum Moisture Content (OMC) exhibit an inverse relationship with the velocity. The crossplots show a good correlation with coefficient of correlation (R) ranges from 0.85 to 0.97. For validation of the empirical equations established, a crossplot of the observed and predicted mechanical properties from the derived seismic velocity show a coefficient of correlation (R) of 0.86, 1.0 and 0.98 for OMC, MDD, and CBR respectively. It may therefore, be concluded that the established empirical equations can be used to determine the analysed mechanical properties using the seismic refraction derived velocity. 

 Academic Journals

 Journal

 Correlation Of Geotechnical Parameters With Geological Formations In A Basement Complex And Its Implications On Civil Structure Foundation

 Akintorinwa O. J. And Oluwole S. T.

 2018

Geotechnical tests were carried out on twenty subsoil samples obtained from ten locations at the depth of 1 and 2 m within Federal University of Technology, Akure, Nigeria. The area is typical of basement complex. The test include; Natural Moisture Content, Grain Size Analyses, Specific Gravity, Atterberg Limits, Compaction, California Bearing Ratio (CBR), and Unconfined Compression Tests. The ten locations where the soil samples were collected were selected across the geological classification of the area. ArcGIS 10.1 software was used to generate maps showing the geotechnical parameters distribution across four geological formations within the area at 1 and 2 m depth. It was observed that the distribution of each geotechnical parameter correlates with the composition of the weathering endproduct of the geology. The rocks underlain the area includes; Migimatite Gneiss, Quartzite, Charnockite and Biotite Granite. The poorest geotechnical parameters were obtained within subsoil underlain by Charnockite, hence are most unsuitable soil to host the foundation of civil engineering structures, while the area underlie by weathering end-product of quartzite rock is of good geotechnical parameters and most suitable soil to host the foundation of civil engineering structures. The weathering end-products of Charnockite, Migimatite and Granite rocks give relatively high shear strength than that of quartzite, indicating low cohesive nature of the weathering end-product of quartzite.

 

 Elsevier

 Journal

 Empirical Relationship Between Electrical Resistivity And Geotechnical Parameters: A Case Study Of Federal University Of Technology Campus, Akure SW, Nigeria.

 Akintorinwa O. J. And Oluwole S. T.

 2018

Electrical resistivity measurement and geotechnical tests were carried out at some locations within The Federal University of Technology, Akure Campus with the aim of establishing an empirical relationship between the two parameters. Ten locations were selected across the geological distribution of the area. Electrical resistivity measurements were carried out at each of the locations by adopting a current electrode separation corresponding to the depth of interest (1 and 2 m). The geotechnical analyses were carried out on twenty (20) subsoil samples taken at the depth of 1 and 2 m at each of the sounding locations. The apparent resistivity values obtained were correlated with the analyzed geotechnical parameters at the depth of 1 and 2 m, and empirical equations relating the two parameters were established. The cross plots show that, the two parameters correlate with the composition of the weathering end-product of the geology within the study area. The cross correlation at the depth of 1 and 2 m show that Speci?c Gravity (SG), Maximum Dry Density (MDD) and California Bearing Ratio (CBR) exhibit a direct relationship with apparent resistivity (?a) while Moisture Content, Clay and Silt Content, Liquid Limit (LL), Plastic Limit (PL), Plasticity Index (PI), Linear Shrinkage (LS), Optimum Moisture Content (OMC) and Uncon?ned Compression Shear (UCS) strength exhibit an inverse relationship. The cross plots at both depths generally give a good correlation with coe?cient of correlation (R) generally greater than 0.50. The fact that almost all the geotechnical parameters gave a relatively good coe?cient of correlation with apparent resistivity implies that reliable engineering geotechnical parameters can be estimated from electrical resistivity measurements using the established empirical equations for each of the parameters. 

 Elsevier

 Journal

 Determination Of Gas Reservoir(s) Using AVO Inversion Within “XY” Field Offshore Niger Delta

 B.S. Ajanaku, O.J. Akintorinwa

 2018

The AVO inversion analysis of pre-stack seismic data of “XY” ?eld located within the offshore, Niger Delta Basin has been considered in this research work with the aim of using AVO inversion to delineate gas reservoirs within the ?eld. Three different inversion techniques are carried out in order to obtain accurate reservoir signature. The conventional AVO inversion analysis of the ?eld do not identify the gas reservoirs clearly as there are other zones without gas with similar signatures, however, the cross-plots analysis of elastic parameters and the inverted volumes are used to delineate two gas reservoirs at 2000 and 2100 ms. Conclusively, the inversion techniques help to map the reservoir zone in a better way by increasing the vertical resolution. AVO inversion analysis as used in this research help for better understanding of the physical properties of the delineated reservoirs. 

 LONGDOM Publishing

 Journal

 Application Of Geophysics In Post Foundation Study: A Case Study Of The Faculty Of Social Science Building, Phase I, Federal University, Oye-Ekiti, Southwestern, Nigeria.

 Aroyehun M Tope And Akintorinwa O James

 2018

Post foundation study of the causes of distress on the Faculty of Social Science building, Phase I, Federal University, Oye-Ekiti was carried out using geophysical approach. The geophysical methods used were the magnetic and electrical resistivity. The magnetic measurements were taking at an interval of 5 m along the established three traverses. The magnetic data were presented as profiles and interpreted using Euler deconvolution software. The Vertical Electrical Sounding data were quantitatively interpreted using partial curve matching technique and 1-D forward modelling with Win Resist software. The dipole-dipole data were inverted using DIPPRO software. The magnetic profiles delineated two subsurface layers; the overburden and the Basement bedrock. Series of geological linear structures were delineated by the ground magnetic. The VES results reveal three subsurface geoelectric layers. These include; the topsoil with resistivity ranging from 20-290 ?m and thickness ranging from 0.4-2.5 m; the weathered layer with resistivity ranging from 2.6-122?m and thickness ranging from 0.9-23 m; and the Basement bedrock with resistivity ranging from 83-??m. The low resistivity values of the Basement bedrock in places indicate an intense fractured basement rock. The 2-D resistivity structure also delineated three geoelectric sequences; the topsoil, the weathered layer and the Basement rock which correlate with the geoelectric sections. Geological linear features were also delineated by the 2-D resistivity imaging which correlates with the magnetic results. The depth on which the foundation of the investigated building was hosted is not known but it is suspected to have been hosted within the weathered layer. This layer predominantly composed of clayey formation which are of high swelling potential and may be subjected to subsidence under heavy load. The causes of distress on the investigated building may have being precipitated by the clayed nature of the layer where the structure was founded and the presence of linear structure suspected to be fractured or fault within the basement. TM