scholarly journals Application of 2-dimensional tomography to investigate subsurface lithology in Auchi polytechnic, auchi, Edo state, nigeria

2020 ◽  
Vol 39 (3) ◽  
pp. 905-910
Author(s):  
C.O. Aigbogun ◽  
D.A. Babaiwa ◽  
B.J.O. Mujakperuo
Keyword(s):  
Maximum Depth ◽  
Electrode Spacing ◽  
Clayey Sand ◽  
Sandy Clay ◽  
Edo State ◽  
Subsurface Resistivity ◽  
Schlumberger Array

The Wenner – Schlumberger array was used for Constant Separation Traversing (CST) to investigate subsurface lithology in Auchi Polytechnic, Auchi. All the traverses were carried out with electrode spacing of 5 m with a spread of 200 m. The data was obtained using Pasi terrameter (16-GL) and processed with the Dipro software. The subsurface resistivity values ranged from 207 Ωm – 8357 Ωm. The results obtained from this survey classified the subsurface lithology into topsoil, clayey sand, sandy clay and sand. The maximum depth penetrated was 50 m. Keywords: Lithology, resistivity, subsurface, Wenner-Schlumberger, 2-Dimensional.

scholarly journals The use of Geoeletric Methods for Post-foundation Assessments of Distressed Buildings in Ebute-meta, Mainland Local Government Area of Lagos State

2021 ◽  
pp. 104-119
Author(s):  
O. J. Airen
Keyword(s):  
Soft Clay ◽  
Maximum Depth ◽  
Silty Sand ◽  
Silty Clay ◽  
Clayey Sand ◽  
Near Surface ◽  
Cone Resistance ◽  
Sandy Clay ◽  
Geotechnical Investigations ◽  
Support Engineering

Geophysical and geotechnical investigations were combined to investigate the immediate causes of the distresses and foundation failures of buildings in Ebute-Meta area of Lagos, south-west Nigeria. Six (6) traverses were mapped in the study area across which six (6) 2D Wenner ERI, and fourteen (14) VES geophysical data were acquired. One (1) boring and five (5) CPT geotechnical data were also acquired. 2D ERI results reveal that resistivity values vary from 4.62 – 293 Ωm across the study area. Three resistivity structures were identified which denoted peat/clay, sandy clay, clayey sand and sand. The resistivity of the peat/clay varies from 4.62 – 27.9 Ωm with thickness varying from 12 - 25 m. The sandy clay varies in resistivity and thickness values from 26 – 86 Ωm and 8 – 29 m respectively. The clayey sand from 84.4 – 182 Ωm and 10 -15 m, and sand, having resistivity and thickness values of 293 Ωm and 3 – 5 m. The VES reveals similar results to the 2D ERI, delineating six geoelectric layers which are the topsoil, peat, clay, sandy clay, clayey sand and sand at maximum depth of 35.8 m. The borehole (BH) reveals a maximum boring depth of 45 m with eight zones comprising dark grey sandy clay, firm to stiff silty clay, soft, dark organic silty peaty clay, grey silty sand, dark grey silty sandy clay, dark grey organic peaty clay, grey silty sandy clay and medium dense to dense grey sand with occasional gravels. The CPT, which penetrated a maximum depth 15.8 m reveal that the cone resistance values vary progressively from 0 – 162 kg/cm2indicating very soft clay to soft clay near-surface and medium dense to dense geologic material at deeper depth. The peat/clay delineated by the 2D ERI and VES at 5 – 25 m depth with resistivity value varying from 4.62 -17 Ωm in the study area, and also revealed in the BH at 5.75 – 27.75 m depth as soft, dark organic silty peaty clay, having cone resistance values varying from 0 – 20 kg/cm2 is laterally extensive and incompetent to support engineering foundation.

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.

scholarly journals Investigation of the Effect of Highway Runoff along Lagos-Badagry Expressway Using Electrical Resistivity Tomography and Physiochemical Methods

2020 ◽  
pp. 42-58
Author(s):  
A. S. Ogungbe ◽  
O. O. Olajuwon ◽  
R. B. Adegbola ◽  
A. A. Alabi ◽  
E. O. Onori ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Electrical Resistivity ◽  
Total Dissolved Solids ◽  
Clayey Sand ◽  
Highway Runoff ◽  
Dissolved Solids ◽  
Southwest Nigeria ◽  
High Level ◽  
Subsurface Resistivity ◽  
2D Resistivity

Geophysical and physiochemical investigations were carried out along Lagos-Badagry Expressway, Southwest, Nigeria on three locations dominated by highway runoff, with a view to monitoring the effect of highway runoff on nearby groundwater. The locations were: Iyana Isashi, Iyana Era and Agbara. An overview of the subsurface resistivity distribution was achieved employing Vertical Electrical Sounding (VES) using Schlumberger array and Two-dimensional (2D) resistivity imaging (Wenner array). The ABEM Terrameter SAS 1000 was used for both VES and 2D resistivity surveys and the data were analysed using IPI2win and RES2DINV, respectively. The VES results showed up to four geoelectric layers consisting of sand, clayey sand, clay and sandy soils. The resistivity at Agbara was found varying from 3.52 Ωm - 11 Ωm. This low resistivity value showed a high level of infiltration of highway runoff into the subsurface, thereby causing contamination of the groundwater. Iyana Isashi and Iyana Era have a relatively moderate resistivity values ranging from 103 Ωm to 178 Ωm. Physiochemical analysis of groundwater samples collected at the study locations revealed high electrical conductivity, total dissolved solids and pH values. The results of the borehole sample taken at 32 m away from the profile point at Agbara produced higher values of electrical conductivity and total dissolved solids than those of other locations, hence validating the electrical resistivity surveys, indicating that the groundwater sample from the survey point at Agbara is contaminated.

scholarly journals Identification of Aquifer Layer Based on 2D Resistivity Data in Lhokseumawe Aceh-Indonesia

2019 ◽  
Vol 8 (3) ◽  
pp. 78-83
Author(s):  
Zul Fadhli ◽  
Muhammad Syukri ◽  
Marwan Marwan
Keyword(s):  
Ground Water ◽  
Sea Water ◽  
Confined Aquifer ◽  
Clayey Sand ◽  
Sea Water Intrusion ◽  
Aceh Province ◽  
On Line ◽  
Aquifer Type ◽  
2D Resistivity ◽  
Schlumberger Array

Penelitian untuk mengidentifikasi keberadaan air tanah dan kedalaman akuifer telah dilakukan di wilayah KEK Arun Lhokseumawe Provinsi Aceh dengan kondisi geologi daerah penelitian adalah batuan lanauan dan batuan lempung serta geomorfologinya berupa perkebunan dan sungai buatan. Penelitian ini mengaplikasikan metode geolistrik resistivitas 2D dengan konfigurasi Wenner-Schlumberger. Akuisisi data di lapangan menggunakan alat SuperSting R8 yang keseluruhannya mempunyai 4 lintasan pengukuran dengan lintasan 1 dan 2 memotong lintasan 3 dan 4, panjang masing-masing lintasan pengukuran tersebut adalah 400 m. Pemprosesan data Hasil akuisisi di lapangan menggunakan software Res2dinv untuk menampilkan model 2D bawah permukaan di lokasi penelitian. Hasil interpretasi menunjukkan lintasan L1 pada kedalaman sampai dengan 70 m terdapat lempung berpasir, lanauan dan gravel. Terdapatnya pengaruh instrusi air laut pada kedalaman 25 m yang ditandai dengan nilai resistivitas 1 Ώm. Lapisan akuifer di identifikasi pada jarak bentangan 100 - 200 m dan pada kedalaman 60 m dengan nilai resistivitas 30 Ωm. Penampang lintasan 3 dan 4 tidak menunjukkan adanya lapisan akuifer yang layak untuk diexploitasi pada lintasan tersebut. Interpretasi lintasan L4 menunjukkan adanya intrusi air laut yang besar pada lapisan pertama. Terdapat 3 lapisan yang kontras yaitu lapisan lempung berpasir, gravel/lempung lanauan dan batuan dasar. Lapisan akuifer pada lintasan 4 diinterpretasikan berada pada kedalaman 70 m dengan nilai resistivitas 30 Ωm. Rekomendasi yang paling layak untuk lokasi pengeboran yaitu pada lintasan 4 pada jarak bentangan 180 m dengan jenis akuifer tertekan. The research to identified ground water and depth of aquifer was conducted in KEK Arun Lhokseumawe Aceh Province. The geology contained siltstone and clay with geomorphology area are plantation and artificial river. The 2D resistivity acquisition was using Supersting R8 equipment with Wenner-Schlumberger array. There are 4 survey lines that conducted in the area where line 1 and 2 were crossed with line 3 and 4. The length of each line is 400 m respectively. The data processing was using Res2dinv software to shows 2D subsurface model. The result shown that line 1 is sandy clay, siltstone and gravel at depths up to 70 m. It was influenced by sea water at depth 25 m with resistivity value of 1 Ωm. The aquifer layer was identified at depth 60 m with resistivity value of 30 Ωm. However, line 3 and 4 were presented that the area surveys are suitable for exploration which have not indicate the existence of an aquifer layer. In the last line, it shown sea water intrusion at the first layer. There are 3 layers that contained in line 4 which is clayey sand, gravel and bedrock. The aquifer layer at Line 4 was interpreted at depth 70 m with resistivity value of 30 Ωm. The most feasible recommendation for a drilling location is on Line L4 at a distance of 180 m with a confined aquifer type. Keywords: Aquifer, Resistivity, Lhokseumawe, ground water, sand

scholarly journals Pencitraan 3D Data Geolistrik Resistivitas dengan Rockworks Berdasarkan Hasil Inversi Res2DInv untuk Mengetahui Persebaran Batuan Konglomerat di Desa Surodadi, Kecamatan Gringsing, Kabupaten Batang

2017 ◽  
Vol 7 (2) ◽  
pp. 111 ◽  
Author(s):  
Taufik Nur Fitrianto ◽  
Supriyadi Supriyadi ◽  
Teguh Maulana Mukromin
Keyword(s):  
Data Acquisition ◽  
3D Imaging ◽  
Research Area ◽  
Electrode Spacing ◽  
Microsoft Excel ◽  
Parallel Lines ◽  
3D Data ◽  
Position Data ◽  
2D Imaging ◽  
Schlumberger Array

<p>Research was conducted to determine distribution of Conglomerate in Surodadi Village, Gringsing, Batang. The data acquisition used Schlumberger array. The length of line is 165 m and 15 m electrode spacing. The data processing used Microsoft Excel and 2D imaging used Res2Dinv. Then 3D imaging used Rockworks from result of Res2DInv inversion. The position data was used on UTM coordinate from position data each of electrode. The data acquisition was done at two parallel lines. In this area was found two types of rocks; tuffaceous sandstone and conglomerate. The conglomerate with resistivity values higher than 180 Wm is distribution on southeast research area at the depth 5 m – 25 m. While the tuffaceous sandstone layers is distribution on northwest research area.</p>

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.

scholarly journals Fractional Current Flow in the Subsurface Using Electrical Resistivity Method: A Laboratory Approach

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
James Adeyemo Adegoke ◽  
Gideon Oluyinka Layade ◽  
Temitayo Kadir
Keyword(s):  
Electrical Resistivity ◽  
Current Flow ◽  
Soil Samples ◽  
Electrode Spacing ◽  
Curve Matching ◽  
Resistivity Method ◽  
Electrical Resistivity Method ◽  
Matching Techniques ◽  
Schlumberger Array ◽  
Effective Penetration

Abstract The authors describe electrical resistivity method using a laboratory experiment, which was conducted in order to calculate the percentage of current that penetrated each layer of soil arranged in a container using Schlumberger array. Four soil samples arranged in three different set-ups were used. The apparent resistivity obtained was interpreted using curve matching techniques and WinResist iteration yielding types A curve, H curve and A curve, respectively. The interpreted data gave the resistivity of each layer and its thicknesses. The thicknesses obtained from the interpretation were at variance with the actual thicknesses arranged in the container. A multiplier was obtained which serves as a constant in other to obtain the actual thickness. The effective penetration depth of current was determined through the calculated thickness of each layer and the known electrode spacing (AB). The percentage of current that penetrates the layers was found to depend on the electrode spacing as well as the thickness of that layer. Thus, a layer with relatively small thickness has a small percentage of current passing through it compared to a thicker layer.

A 3-D geoelectric model over mineralized zone of Ugonoba, Edo State, Nigeria

2021 ◽  
Vol 20 (1) ◽  
pp. 141-150
Author(s):  
V.B. Olaseni ◽  
J.O. Airen
Keyword(s):  
Mineral Resources ◽  
Electrode Spacing ◽  
High Resistivity ◽  
Clayey Sand ◽  
Resistivity Method ◽  
True Resistivity ◽  
Geological Features ◽  
Mineralized Zone ◽  
Formed Part ◽  
Block Models

The occurrence of solid minerals in Ugonoba community was investigated using the 3D electrical resistivity method. Data was acquired  using PASI 16GL Terrameter using the wenner electrode configuration with a view to delineating mineral deposits in the study area.  During the reconnaissance survey, the outlook of some geological features in the form of outcrops on the surface formed part of the motivation for the geophysical survey within the Ugonoba area. Ten traverses of 200 m maximum spread and 10m electrode spacing with total depth of 40.07 m were obtained in the study area to form a square grid. The acquired data was first processed and inverted using RES2DINV software to generate ten 2-D model images and later collated into 3-D using the inversion code of RES3DINV software which automatically determines a horizontal 3D depth slice, cubes and block models of resistivity distribution. These models generated were interpreted and used to ascertain the true resistivity, lithologic formation, depth extent to any buried mineral and aggregate deposited in the study area. The extracted 3D model images revealed evidence of some geological materials/minerals in the study area which fall within the high resistivity range of 2500 Ωm to 14376 Ωm. It can therefore be inferred from the standard resistivity table that the lithology of study area is composed of non-metallic type of mineral resources which are: clayey sand, lateritic clayey sand,  sandstone and limestone. The estimated quantity in metric ton for the dominant lithology (sandstone, granite and limestone) is ± 10% of 1,257,142.9 which can be commercially explored. Keywords: Wenner-wenner array, outcrop, minerals, RES3DINV, block models.

scholarly journals Integrated Geotechnical and Geophysical Investigation of a Proposed Construction Site at Mowe, Southwestern Nigeria

2018 ◽  
Vol 64 (3) ◽  
pp. 21-29
Author(s):  
Kayode F. Oyedele ◽  
Sunday Oladele ◽  
Adaobi C. Nduka
Keyword(s):  
Standard Penetration Test ◽  
Thin Layers ◽  
Electrode Spacing ◽  
Silty Clay ◽  
Geophysical Investigation ◽  
Clayey Sand ◽  
Deep Foundation ◽  
Southwestern Nigeria ◽  
Lateritic Clay ◽  
Wenner Array

Abstract The subsurface of a proposed site for building development in Mowe, Nigeria, using Standard Penetration Test (SPT), Cone Penetrometer Test (CPT) and Horizontal Electrical Profiling (HEP), was investigated with the aim of evaluating the suitability of the strata for foundation materials. Four SPT and CPT were conducted using 2.5 tonnes hammer. HEP utilizing Wenner array were performed with inter-electrode spacing of 10 – 60 m along four traverses coincident with each of the SPT and CPT. The HEP data were processed using DIPRO software and textural filtering of the resulting resistivity sections was implemented to enable delineation of hidden layers. Sandy lateritic clay, silty lateritic clay, clay, clayey sand and sand horizons were delineated. The SPT “N” value defined very soft to soft sandy lateritic (<4), stiff silty lateritic clay (7 – 12), very stiff silty clay (12 - 15), clayey sand (15-20) and sand (27 – 37). Sandy lateritic clay (5-40 kg/cm2) and silty lateritic clay (25 - 65 kg/cm2) were defined from the CPT response. Sandy lateritic clay (220-750 Ωm), clay (< 50 Ωm) and sand (415-5359 Ωm) were delineated from the resistivity sections with two thin layers of silty lateritic clay and clayey sand defined in the texturally filtered resistivity sections. Incompetent clayey materials that are unsuitable for the foundation of the proposed structure underlain the study area to a depth of about 18m. Deep foundation involving piling through the incompetent shallow layers to the competent sand at 20 m depth was recommended.

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