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Dipole-dipole pseudosection along traverse three.

Dipole-dipole pseudosection along traverse three.

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This research was carried out within the Basement Complex terrain along Oluwole, off Akure High School, Akure, Ondo State, Nigeria, with the aim to ascertain the reasons for the major cracks and sign of apparent failures observed in a building few years after its construction and usage. The geophysical investigation involved two electrical resistiv...

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Context 1
... pseudosection along traverse three Figure 6 was taken at the west eastern part of the investigated area with a distance of 25 m from traverse two and located at the lower path (southern end) of the study area. It covers a distance of 100 m and also exhibits a unique characteristic of having a shallow overburden of extremely weak material that cannot withstand the activities of stress and strain. ...
Context 2
... pseudosection along traverse three Figure 6 was taken at the west eastern part of the investigated area with a distance of 25 m from traverse two and located at the lower path (southern end) of the study area. It covers a distance of 100 m and also exhibits a unique characteristic of having a shallow overburden of extremely weak material that cannot withstand the activities of stress and strain. ...

Citations

... Electrical Resistivity method has been found to be a significant tool in researches that includes; detection of bedrock voids, soil and bedrock property characterization, mapping the soil-bed interface, and fractures among other investigations (William and Ted, 2004;Adebiyi et al., 2019;Adebo et al., 2019;Bawallah et al., 2020;Adebo et al., 2021). Electrical Resistivity method has been applied to fundamental problems associated with porous and saturated media for many years (Hilchie, 1982). ...
... Electrical Resistivity method has been found to be a significant tool in researches that includes; detection of bedrock voids, soil and bedrock property characterization, mapping the soil-bed interface, and fractures among other investigations (William and Ted, 2004;Adebiyi et al., 2019;Adebo et al., 2019;Bawallah et al., 2020;Adebo et al., 2021). Electrical Resistivity method has been applied to fundamental problems associated with porous and saturated media for many years (Hilchie, 1982). ...
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This research work asses the problems of building foundation within Sagari Estate, Akure, Southwestern Nigeria, using remotely sensed data and geophysical methods. The slope, lineament, hill, and contour map were generated using terrain analysis in ArcGIS 10.5 environment. Electrical Resistivity (ER) and Very Low Frequency (EM-VLF) Electromagnetic methods were used in this study. The ER method involves the use of Vertical Electrical Sounding (VES) with Schlumberger configuration. The initial geoelectric parameters obtained from the fifty three (53) VES station points interpretation (layer resistivities and thicknesses) were used to generate geoelectric maps. The variation of strata and physical strength information within the investigated area were determined from the integrated results of the three methods. Results revealed that substantial portion of the areas studied is relatively unsuitable for high rise civil engineering foundations. However, it was showed that the northern and southern parts of the investigated area were more suitable for foundations. The dominant presence of lineaments, steep slopes , fractures, streams, and thick clayey topsoil as well as weathered layers within the western, eastern, and the central portions reveals susceptibility to subsidence if adequate structural supports mitigate the effect of the persistent foundation failure are not provided.
... Several types of research on vulnerability assessment have illustrated that the protection of porous media on the permeability of the overlying layer to the transportation of contaminants into underlying aquifer regions [12][13][14][15][16][17][18]. In the crystalline Basement Complex region, many heeds have been given to the morphology of the vadose zone in delineating the susceptibility of subsurface geological properties underlying aquifers to infiltration of contaminants [19][20][21][22][23][24][25]. The flow and extent of contaminant infiltration are controlled majorly with ease by the extent to which the underlying region beneath the location allows penetration of contaminant. ...
... The Electrical Resistivity method involving Vertical Electrical Sounding (VES) technique utilizing Schlumberger configuration was adopted for these research. Twenty (20) VES points were carried out across the study area with the current electrode spacing (AB/2) of 65 m ( Figure 3). The Electrical Resistivity data was processed by plotting apparent resistivity against the electrode spread (AB/2). ...
... The terrain of Lead City University is generally undulating but flat in some areas. Twenty (20) Vertical Electrical Sounding points were carried out, processed, and interpreted quantitatively and qualitatively. Three subsurface geoelectric layers were delineated namely: the topsoil, weathered layer, and fresh basement. ...
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This research evaluates aquifer vulnerability within Lead City University Ibadan, Southwestern Nigeria. Multi-Criteria Evaluation Techniques were used for obtaining this aim, with the model which is based on hydraulic conductivity, longitudinal conductance, topsoil resistivity, and thickness of layer overlying aquifer of each sounding point within the entire investigated area for future groundwater development. Electrical Resistivity method using Vertical Electrical Sounding (VES) techniques was obtained across the investigated area using Schlumberger configuration. Twenty (20) VES data points were acquired using Omega Resistivity Meter with maximum current electrode separation (AB/2) of 65 m. The geoelectric results were used to determine second-order parameters and subsequently used to model different geoelectric maps. Three subsurface geoelectric layers were delineated across the investigated area which comprises topsoil, weathered layer, and fresh basement. In this research work, four different aquifer vulnerability parameters; Topsoil Resistivity (TSR), Longitudinal Conductance (LC), Thickness of Layer Overlying Aquifer (TLOA), and Hydraulic Conductivity (HC) were generated and integrated to model the aquifer vulnerability map. It was observed that a small closure at the southwestern and northeastern parts is indicative of a high aquifer vulnerability zone. Moderate aquifer vulnerability zone was observed at the northeastern, southwestern, and western parts of the study area, while low aquifer vulnerability zone was observed at the northern, southern, southeastern, southwestern, central, northeastern, and northwestern parts of the study area. Also, a very low aquifer vulnerability zone was observed in the southwestern part of the study area. The results obtained, indicates that the investigated area is an area of low aquifer vulnerability.
... The issues concerning foundation studies have remained a burning concern in the mind of geoscientists and civil engineers . Whereas, the spates of foundation vulnerability and subsequent failures that were reported in some parts of African and especially Nigeria has assumed a worrisome dimension, hence to evaluate the factors that are responsible for this foundation vulnerability in terms of depth of investigations, nature of materials, structural trends, geodynamic factors, the relevance of Electrical Resistivity and Geotechnical attributes and their significance in evaluation of foundation sustainability Bawallah et al., 2019a;Bawallah et al., 2019b;Bawallah et al., 2020;Oyedele et al., 2020). ...
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This research evaluates the significance of geotechnical and Electrical Resistivity methods in studying structural integrity as fundamental factors that may account for failure in a typical sedimentary environment of Ukpenu Primary School, Ekpoma, Edo State, Nigeria. Two methods were used in this study such as the Electrical Resistivity approach involving the use of Lateral Horizontal Profiling (LHP), 2D Electrical Resistivity Tomography (ERT), and Vertical Electrical Sounding (VES) techniques. While geotechnical method involved the collection of soil samples from the study locations for the characterization of the soil properties that are very vital to foundation studies. Nine VES were carried out using Schlumberger array with current electrode spacing varying from 1 to 40 m, with 2-D ERT using Dipole-Dipole electrode array with inter-station separation of 5 m and an expansion factor varied from 1 to 5 while LHP involve Wenner array with an electrode spacing of 5 m interval and was used to determine the vulnerability factors for the building sustainability. The VES interpretation results were used to determine the second-order parameters for the determination of vulnerability. The results obtained from the two methods review that both are very fundamental to foundation dynamics. However, electrical attributes were found to give better information in terms of depth, lateral extent, layer stratification, and nature of materials which make it an indispensable tool over geotechnical attributes whose depth of investigation is up to a maximum of 5 m which poses great limitation in the evaluation of structural integrity, against stress, and strain occasion by geodynamic activities that often result into fracture, crack, highly weathered formation that usually goes beyond the shallow depth of investigation. Therefore, it can be stated that resistivity attributes account for 90% of the major contributing factors that affect foundation vulnerability.
... The results obtained from both methods gave relevant information on factors that were responsible for cracks/subsidence and failure of the building. affected other geodynamic activities, leading to increase in rainfall, erratic distribution of rainfall, sudden changes in erosion pattern, incidence of Earthquake and tremor, sudden rise in sea level, increase in desertification, sudden changes in sea tides and a host of others related with its direct consequences on the safety of man and his environment Bawallah et al., 2019b;Ozegin et al., 2019a;Oyedele et al., 2020;Bawallah et al., 2020). ...
Article
This study has evaluated the immediate and remotes causes of structural/foundation failures arising as a result of geodynamic activities that often bring about weathering/fracturing process. Three geophysical techniques were deployed and complemented with geotechnical analysis. The geophysical techniques include 2-D imaging using Dipole-Dipole, Lateral Horizontal Profiling technique which give useful information on the nature and trends of the sub-surface and structural trends and Vertical Electrical Sounding technique using Schlumberger electrode configuration which gave relevant information on layer sequences/stratification as well as variations in lithology/lithological distributions. The geotechnical analysis gave relevant information on the nature, types, grain size analysis and other soil parameters that has direct impact on foundation integrity. The results obtained from the Dipole-dipole and Wenner techniques indicated six weak zones of major interest while the Vertical Electrical Sounding delineated three major layers which are topsoil, clayey sand/ sandy and moderately resistive sandstone formation. The geotechnical analysis indicated the results obtained from both field and laboratory tests which shown that the specific gravity ranged from 2.64 to 2.65; linear shrinkage ranged from 5.0 to 7.1;the amount of fines (i.e. particles less than 0.075mm sieve) from the particle size analysis test ranged from 34.4% to 36.7%; liquid limit varied from 29.4% to 32.2%; Plasticity index varied from 10.2 to 11.9; from the compaction test optimum moisture content and maximum dry density varied from 13.6% to 14.2% and 19.38kN/m3 to 19.49kN/m3 respectively; unconfined compressive strength range from 181kPa to 227kPa. The results obtained from both methods gave relevant information on factors that were responsible for cracks/subsidence and failure of the building
... The results obtained from both methods gave relevant information on factors that were responsible for cracks/subsidence and failure of the building. affected other geodynamic activities, leading to increase in rainfall, erratic distribution of rainfall, sudden changes in erosion pattern, incidence of Earthquake and tremor, sudden rise in sea level, increase in desertification, sudden changes in sea tides and a host of others related with its direct consequences on the safety of man and his environment Bawallah et al., 2019b;Ozegin et al., 2019a;Oyedele et al., 2020;Bawallah et al., 2020). ...
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An integrated geophysical study has been carried out for the evaluation of geological factors that are responsible for foundation stability and vulnerability to failure in a typical sedimentary environment. This is a direct consequence of structural failure that was becoming a matter of almost daily occurrence, especially during the rainy season. In carrying out this study, seven electromagnetic profiles, magnetic as well as Lateral Horizontal Profiling (LRP) were carried out and complimented with Vertical Electrical Sounding (VES). The profiling allowed for the structural delineation of the areas into weak, fairly weak, fairly competent, competent, and very competent zones, while the Vertical Electrical Sounding (VES) delineated the subsurface layer parameters into topsoil, clay horizon, sand, and resistive sand. The vulnerability factors obtained from the statistical analysis were used to determine the stability and generate standardize threshold values. Therefore, since the load-bearing capacity of the foundation of this area is largely dependent on the second layer which is highly incompetent from this study, it then becomes imperative that the ingenuity of the construction/civil engineer must be brought into bearing for the sustainability and stability of any structure in this study area. All the methods engaged in this study exhibits an effective correlation and the area could be inferred/observed to be highly vulnerable to failure as a result of the inherent weak nature of the study location.
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This research was carried out within Institute of Agriculture Research and Training Moor Plantation Ibadan, Southwestern Nigeria, with the aim to ascertain suitability of the proposed site for building construction and usage. The geophysical investigation involved three electrical resistivity techniques; Vertical Electrical Sounding (VES) using the Schlumberger configuration, 2D ERT and 2-D electrical imaging using Dipole-dipole electrode configuration. Two traverses were established E–W direction cutting across geologic strike with a distance of 80 m and of varying inter-traverse spacing. Eight (8) VES stations were occupied covering the entire study area for layer stratification and geoelectric parameters. The results were qualitatively and quantitatively interpreted and are presented as sounding curves and geoelectric sections. The 2-D imaging gave information on the subsurface characteristic in the area with generally low apparent resistivity indicating low competence material. The results obtained from the VES delineate three geoelectric units which comprise of the topsoil, weathered layer and fresh basement. The results from the VES were used to determine the second order parameters. The entire results correlate well with one another showing that all the techniques used were complemented. This study has further justified the need for geophysical site investigation as pre-condition before any construction to avoid problems of differential settlement. In determining of foundation material, topography elevation, clay content and the depth of weak zones should be put into consideration, since the depth of the weak zone is appreciably high.