scholarly journals Electrical Resistivity and Geotechnical Attributes and The Dynamics of Foundation Vulnerability

2021 ◽  
Vol 1 (2) ◽  
pp. 84-97
Author(s):  
Musa Adesola Bawallah ◽  
Stephen Olubusola Ilugbo ◽  
Kesyton Oyamenda Ozegin ◽  
Babatunde A Adebo ◽  
Isaac Aigbedion ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Structural Integrity ◽  
Sedimentary Environment ◽  
Electrode Array ◽  
Electrode Spacing ◽  
Contributing Factors ◽  
Current Electrode ◽  
Lateral Extent ◽  
Indispensable Tool ◽  
Depth Of Investigation

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.

scholarly journals Modeling of Subsurface Integrity Using Dar-Zarrouk Parameters: A Case Study of Ikekogbe UBE Primary School, Ekpoma, Edo State, Nigeria

2019 ◽  
pp. 1-17
Author(s):  
Bawallah Musa Adesola ◽  
Ilugbo Stephen Olubusola ◽  
Aigbedion Isaac ◽  
Aina Adebayo O. ◽  
Oyedele Akindele Akintunde
Keyword(s):  
Electrical Resistivity ◽  
Primary School ◽  
Electrode Array ◽  
Electrode Spacing ◽  
Weak Zone ◽  
Current Electrode ◽  
Resistivity Method ◽  
Edo State ◽  
Structural Failures ◽  
Dar Zarrouk Parameters

In this present study area, most building failures often start with minor/major cracks which widen over time, and it is often followed by post construction remedial measures which fail after sometime, thereby leading to total collapse and sinking of such buildings. The research was carried out in order to be able to unravel the causes of major cracks along the side of a major class room block at Ikekogbe, UBE Primary School, Ekpoma, Edo State, Nigeria in less than five (5) years after it was constructed. The cracks were visible both at the front and at the back of the building along the same axis and almost at this same distance as it was at the front of the building. The investigation involved Electrical Resistivity method using three techniques; Vertical Electrical Sounding (VES), 2-D Electrical Resistivity Tomography (ERT) and Horizontal Profiling (HP). The traverses were established along E-W directions and Eight (8) 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 that varied from 1 to 5 and HP using Wenner array with an electrode spacing of 5 m interval. The VES interpretation results were used to determine the second order parameters for modeling of subsurface integrity/competence. The 2 D imaging (Dipole-Dipole) gave information on the subsurface characteristic and the Wenner profile was characterised by low resistivity at the region of 30 to 45 m considered as the weak zone. Correlating the results with subsurface integrity model along traverses one and three, there was a high degree of correlation as this region coincides with the very low/low integrity/competence with the foundation of the classroom overlying this layers. The research revealed that the problem of structural failures/crack noticed along the building walls and axis was not as a result of human problem alone but mainly the existence of very low/low integrity/competence layers which contributed greatly to the cracks observed on the classroom block. These results reveal that the three Electrical resistivity techniques used for this study are complimentary to each other.

Exploration for Marble Deposit in Parts of Okpella, South-Southern Nigeria

2019 ◽  
pp. 1-7
Author(s):  
K. O. Ozegin
Keyword(s):  
Electrical Resistivity ◽  
Electrode Spacing ◽  
Clayey Sand ◽  
Current Electrode ◽  
Electrical Resistivity Survey ◽  
Resistivity Method ◽  
Resistivity Survey ◽  
Surface Measurements ◽  
Electrical Sounding ◽  
Electrical Resistivity Method

The ultimate aim of the electrical resistivity survey is to determine the resistivity distribution with depth on the basis of surface measurements of the apparent resistivity and to interpret it in terms of geology. Marble deposit was investigated with the application of electrical resistivity method using Vertical Electrical Sounding (VES) technique with the aim of characterising this deposit in parts of Okpella. Six (6) VES were acquired using the Schlumberger array for data acquisition with current electrode spacing varying from 1.0 to 150.0 m. The VES data obtained were interpreted using ipi2win Software. The results showed three layers indicating subsurface geologic sequence probed 26.4 m and beyond with clay/clayey sand (23.3 – 219.1 Ωm), sand (423 - 2040 Ωm) and marble (12661 - 404498 Ωm). The occurrence of marble deposit was revealed at VES points at 1, 2 and 5 in the studied area.  This study concluded that the study area had occurrence of the marble deposits, which would be of economic importance, if exploited.

Surface-downhole electrical resistivity tomography applied to monitoring of CO2 storage at Ketzin, Germany

Geophysics ◽  
2012 ◽  
Vol 77 (6) ◽  
pp. B253-B267 ◽  
Author(s):  
Peter Bergmann ◽  
Cornelia Schmidt-Hattenberger ◽  
Dana Kiessling ◽  
Carsten Rücker ◽  
Tim Labitzke ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Electrical Resistivity Tomography ◽  
Co2 Storage ◽  
Electrode Array ◽  
First Year ◽  
Index Method ◽  
Resistivity Tomography ◽  
Reservoir Sandstones ◽  
Lateral Extent ◽  
Downhole Measurements

Surface-downhole electrical resistivity tomography (SD-ERT) surveys were repeatedly carried out to image [Formula: see text] injected at the pilot storage Ketzin, Germany. The experimental setup combines surface with downhole measurements by using a permanent electrode array that has been deployed in three wells. Two baseline experiments were performed during the site startup and three repeat experiments were performed during the first year of CO2 injection. By the time of the third repeat, approximately 13,500 tons of [Formula: see text] had been injected into the reservoir sandstones at about 650 m depth. Field data and inverted resistivity models showed a resistivity increase over time at the [Formula: see text] injector. The lateral extent of the related resistivity signature indicated a preferential [Formula: see text] migration toward the northwest. Using an experimental resistivity-saturation relationship, we mapped [Formula: see text] saturations by means of the resistivity index method. For the latest repeat, [Formula: see text] saturations show values of up to 70% near the injection well, which matches well with [Formula: see text] saturations determined from pulsed neutron-gamma logging. The presence of environmental noise, reservoir heterogeneities, and irregularities in the well completions are the main sources of uncertainty for the interpretations. The degradation of the permanently installed downhole components is monitored by means of frequently performed resistance checks. In consistency with the SD-ERT data, these resistance checks indicate a long-term resistivity increase near the [Formula: see text] injector. In conclusion, the investigations demonstrate the capability of surface-downhole electrical resistivity tomography to image geologically stored [Formula: see text] at the Ketzin site.

scholarly journals Geoelectrical Investigation of Subsurface Structures for Mapping Groundwater Potential of Joseph Ayo Babalola University Campus Environment, Ikeji Arakeji, Osun State, Southwestern Nigeria

2019 ◽  
pp. 1-12
Author(s):  
O. E. Odeyemi ◽  
O. M. Odeyemi ◽  
S. A. Owolabi ◽  
E. A. Mamukuyomi ◽  
R. A. Salako
Keyword(s):  
Electrode Array ◽  
Groundwater Potential ◽  
Vertical Electrical Sounding ◽  
Electrode Spacing ◽  
Clayey Sand ◽  
Southwestern Nigeria ◽  
Current Electrode ◽  
Campus Environment ◽  
Lateritic Clay ◽  
Electrical Sounding

Owing to fast increase in number of staff and students of Joseph Ayo Babalola University, Ikeji Arakeji, Southwestern Nigeria, it is therefore very important to carry out this research in order to recommend the actual locations where boreholes can be sunk for good potential yields of groundwater when the time comes. The aim of this research is to carry out vertical electrical sounding geophysical survey at study area with a view to determining good aquifers that are good for the accumulation of groundwater. The study area is located between latitude 0820225 m to 0820345 m (UTM) Northings and longitude 717320 m to 717450 m (UTM) Eastings. Schlumberger electrode array was employed for the study using Ohmega Resistivity meter for the data acquisition. The geoelectric survey of the study area comprised of twelve vertical electrical soundings, with maximum current electrode spacing (AB) of 100 m. The modeled curves are mainly KH-type. The geoelectric sections generated from the sounding curves revealed 4 major layers earth models. The topsoil is made up of clay, clayey sand/lateritic sand with resistivity and thicknesses varying from 54.7 – 210.1ohm-m and 0.2 –0.8m respectively. The second layer is the lateritic clay with resistivities and thicknesses varying from 334 – 963ohm-m and 1.5 – 10.8m respectively. The third layer constitutes the clay / sandy fractured quartzite and it serves as the aquifer unit. The resistivity values lie between 71.7 and 498 ohm-m while the thicknesses vary from 2.1 – 76.3 m. The fourth layer is the fractured/presumably fresh basement bedrock with the resistivity varying from 1879 – 13991.8 ohm-m. Areas characterized with fractured basement of low resistivity with appreciable thickness are therefore recommended for the siting of boreholes. It is concluded that the vertical electrical sounding points of the study area are good aquifers for groundwater accumulation.

scholarly journals Assessment of Hydrogeological Potential and Aquifer Protective Capacity of Odeda, Southwestern Nigeria

2020 ◽  
Vol 66 (3) ◽  
pp. 199-209
Author(s):  
J.O. Aina ◽  
O.O. Adeleke ◽  
V. Makinde ◽  
H.A. Egunjobi ◽  
P.E. Biere
Keyword(s):  
Groundwater Resources ◽  
Electrode Array ◽  
Electrode Spacing ◽  
Protective Capacity ◽  
Clayey Sand ◽  
Southwestern Nigeria ◽  
Current Electrode ◽  
Ogun State ◽  
Weathered Layer ◽  
Longitudinal Unit Conductance

AbstractHydrogeological assessment of groundwater resources was carried out with a view to evaluate the potential of the aquifers to provide portable water supply and access the distribution of electrical parameters of hydrogeologic units in some areas in Odeda, Ogun State, Nigeria. A geophysical survey using vertical electrical sounding (VES) with the Schlumberger electrode array, with half-current electrode spacing (AB/2) varying from 1 to 132 m was carried out at 30 different stations in the study area. The VES data were interpreted qualitatively and quantitatively. Three-to-five sub-surface layers consisting of topsoil, weathered layer consisting of clay, sandy clay, clayey sand and sand layers, and fractured/fresh basement were delineated. Layer resistivities and thicknesses obtained on the curves within the study area showed one main aquifer type, which is the fractured basement. The longitudinal unit conductance (ranging from 0.049720 to 1.4520000 mhos) of the study area aided the protective capacity to be rated into good, moderate and weak. About 33% of the study area falls within the weak protective capacity, 57% falls within the moderate protective capacity and 10% falls within the good protective capacity.

scholarly journals 2-D Electrical Resistivity Imaging Survey for Lithological Assessment at Igwete Primary School, Amai, South-South Nigeria

2021 ◽  
Vol 25 (5) ◽  
pp. 823-827
Author(s):  
V.C. Enebeli ◽  
C.N. Okorafor ◽  
R.E. Kolagbodi
Keyword(s):  
Electrical Resistivity ◽  
Primary School ◽  
Electrode Array ◽  
Lateral Position ◽  
Electrical Resistivity Imaging ◽  
Clayey Sand ◽  
Near Surface ◽  
Resistivity Imaging ◽  
Lateral Extent ◽  
2D Resistivity

Electrical Resistivity Imaging (ERI) is a useful near-surface imaging technique, which mainly include data acquisition, numerical modelling and tomographic inversion. Within the study area, only one – dimensional (1-D) Electrical Resistivity survey has been carried out for Geophysical investigations. Therefore, 2-D ERI survey was carried out at the Igwete Primary School, Amai to provide electrical picture of the subsurface from which discrete bodies and lithology are better revealed vertically and in lateral extent. The 2-D ERT survey data were acquired using the Petrozenith Earth Resistivity meter while employing the Wenner electrode array. The 2-D apparent resistivity data were inverted to obtain true resistivities of the subsurface using res2dinv software running on personal computer. The subsurface resistivity models were displayed as pseudo sections and inverted resistivity section in the form of colour shaded contour maps. The inverse resistivity model images indicate that at a lateral extent in the range (15.00-21.00) m and (33.00-39.00) m, anomalies suspected to be gravel mixed with sand is in place with resistivities of about (254.00-948.00) Ωm. From the geologic section we can infer that a geological formation is observed at a lateral position of (27.00-32.00) m of resistivity in the range (90.00-93.00) Ωm. This structure is inferred to be a clay pocket. The sandy nature of the formation requires that underground water development be sought for at (9.00-15.00) m over a depth (2.30-8.00) m in the sandy environment. Results of 2D resistivity imaging has helped to delineate the lithology which comprise mainly of; sand, sandy clay, clayey sand depositional environment. The resistivity of these lithology falls in the range (90.00-93.00) Ωm with depth to formation of about (2.30-6.00) m.

scholarly journals Geo-electrical investigation of the groundwater potential of Ogidi and environs, Anambra State, South-eastern Nigeria

2021 ◽  
Vol 11 (3) ◽  
pp. 1053-1067
Author(s):  
C. C. Onyekwelu ◽  
C. N. Onwubuariri ◽  
T. I. Mgbeojedo ◽  
L. S. Al-Naimi ◽  
B. I. Ijeh ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Groundwater Potential ◽  
Electrode Spacing ◽  
Current Electrode ◽  
Anambra State ◽  
Electrical Investigation ◽  
Resistivity Method ◽  
Maximum Current ◽  
Electrical Resistivity Method ◽  
Water Saturated

AbstractThe electrical resistivity method was used to determine the groundwater potential of Ogidi and its environs. Thirteen soundings were carried out at thirteen different locations using the ABEM terrameter (SAS 1000), and adopting the Schlumberger configuration with maximum current electrode spacing of 1000 m. The lithologic logs for the boreholes were used to delineate the geologic sections. The results revealed six to nine geo-electric layers comprising laterite, clayey sandstone, sandstone, water-saturated sandstone and shale. The water-saturated sandstone forms the aquiferous unit. This unit was found to have resistivity values ranging from 363Ωm to 9107Ωm. It is deeply seated in some areas with a depth of 33.2–103 m. It was observed that the hydraulic conductivity varies between 0.001 and 0.066 m/day, while the transmissivity values vary between 0.01 and 4.7 m2/day. Among all the VES points studied, it was observed that VES 1 has the highest transmissivity value and the highest aquifer thickness. In view of the foregoing, it is expected that water will flow more from aquifer in VES 1 since groundwater flow from an aquifer is directly proportional to transmissivity.

Geophysical Survey as a Surface Tool in Groundwater Exploration in Delta North District, Nigeria

2011 ◽  
Vol 367 ◽  
pp. 795-800
Author(s):  
F.O. Ezomo ◽  
C.N. Akujieze
Keyword(s):  
Research Work ◽  
Electrode Array ◽  
Water Shortage ◽  
Groundwater Exploration ◽  
Geophysical Survey ◽  
Vertical Electrical Sounding ◽  
Electrode Spacing ◽  
Current Electrode ◽  
Resistivity Method ◽  
Electrical Sounding

Geophysical survey based on electrical resistivity method employing the techniques of vertical electrical sounding (VES) was carried out in order to investigate Groundwater existence in Delta North District, of Nigeria. This research work became necessary in order to solve the problem of acute water shortage in the area by way of prospecting or searching for additional aquifers which would subsidize the existing one, domestically, industrially and agriculturally. Ten (10) vertical electrical sounding (VES) (uniformly distributed) tests were conducted in the area and its environs using “Schlumberger” electrode array. The VES were carried out with half current electrode spacing with the spread Im-928m at six (06) points per decade. The results of the interpretation identified wet sand/clean sand as perched aquifer which can deliver ground water to the bore-hole at perceptible rates between depths of 85m to 145m below sea level. The resistivity of the aquifer detected varied from 95.0 ohm-m to 110,000 ohm-m while the thickness ranged from 30.0m to 105.0m.

ELECTRICAL RESISTIVITY METHOD APPLIED TO STUDY GROUNDWATER CONTAMINATION AROUND THE ALAGOINHAS CEMETERY, BAHIA, BRAZIL

2016 ◽  
Vol 33 (3) ◽  
Author(s):  
Eduardo M.S. Amarante ◽  
Olivar A.L. de Lima ◽  
Susana S. Cavalcanti
Keyword(s):  
Electrical Resistivity ◽  
Groundwater Contamination ◽  
Electrode Array ◽  
Hydrological Conditions ◽  
Vertical Electrical Soundings ◽  
Resistivity Method ◽  
Electrical Soundings ◽  
Electrical Resistivity Method

ABSTRACT. To investigate the subsurface geological and hydrological conditions around the area of the Alagoinhas county cemetery – Bahia State, Brazil, 38 vertical electrical soundings using Schlumberger electrode array were performed to a maximum AB/2 spacing... RESUMO. Para investigar as condições geológicas e hidrológicas da subsuperfície na área do entorno do Cemitério Municipal de Alagoinhas, Bahia, foram realizadas 38 sondagens elétricas verticais centradas em pontos acessíveis da área. As sondagens foram...

scholarly journals Effect of the Geometrical Constraints to the Wenner Four-Point Electrical Resistivity Test of Reinforced Concrete Slabs

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4622
Author(s):  
Kevin Paolo V. Robles ◽  
Jurng-Jae Yee ◽  
Seong-Hoon Kee
Keyword(s):  
Experimental Investigation ◽  
Electrical Resistivity ◽  
Reinforced Concrete ◽  
Concrete Slab ◽  
Plain Concrete ◽  
Electrode Spacing ◽  
Concrete Slabs ◽  
Reinforced Concrete Slabs ◽  
Spacing Ratio ◽  
Geometrical Constraints

The main objectives of this study are to evaluate the effect of geometrical constraints of plain concrete and reinforced concrete slabs on the Wenner four-point concrete electrical resistivity (ER) test through numerical and experimental investigation and to propose measurement recommendations for laboratory and field specimens. First, a series of numerical simulations was performed using a 3D finite element model to investigate the effects of geometrical constraints (the dimension of concrete slabs, the electrode spacing and configuration, and the distance of the electrode to the edges of concrete slabs) on ER measurements of concrete. Next, a reinforced concrete slab specimen (1500 mm (width) by 1500 mm (length) by 300 mm (thickness)) was used for experimental investigation and validation of the numerical simulation results. Based on the analytical and experimental results, it is concluded that measured ER values of regularly shaped concrete elements are strongly dependent on the distance-to-spacing ratio of ER probes (i.e., distance of the electrode in ER probes to the edges and/or the bottom of the concrete slabs normalized by the electrode spacing). For the plain concrete, it is inferred that the thickness of the concrete member should be at least three times the electrode spacing. In addition, the distance should be more than twice the electrode spacing to make the edge effect almost negligible. It is observed that the findings from the plain concrete are also valid for the reinforced concrete. However, for the reinforced concrete, the ER values are also affected by the presence of reinforcing steel and saturation of concrete, which could cause disruptions in ER measurements

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