Constraining Causes of Structural Failure Using Electrical Resistivty Tomography (ERT): A Case Study of Lagos, Southwestern, Nigeria

Ayolabi, Elijah A.; Folorunso, Adetayo Femi; Oloruntola, Moroof O.

doi:10.4133/1.3445528

Cited by 8 publications

(13 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Similar pocket of high resistivity material in the near surface of profile line cut along access road has been attributed to exotic materials (broken blocks, bricks and stones) usually used for land reclaimation or temporary road construction (Ayolabi et al, 2010c). Beneath the clay layer is a thin sandy clay horizon having resistivity of 160Ωm-250Ωm, which serves as a transition zone for the upper clay layer and the lower sandy layer.…”

Section: Electrical Resistivity Tomography (Ert) Resultsmentioning

confidence: 99%

“…These include groundwater exploration (Ayolabi, Folorunso, Eleyinmi, & Anuyah, 2009c), mapping subsurface structures (Khali, 2009), geotechnical and engineering site investigations (Giao, Chung, Kim & Tanaka, 2003;Akintorinwa & Adesoji, 2009;Ayolabi, Folorunso, & Oloruntola, 2010c;Folorunso, Ayolabi, Ariyo, & Oyebanji, 2012), exploration and evaluation of ore deposit (Ramazi, Nejad, & Aenollah, 2009), mapping soil and groundwater contamination (Cahyna, Mazac, & www.ccsenet.org/esr Earth Science Research Vol. 2, No.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Application of Electrical Resistivity Tomography in Mapping Subsurface Hydrocarbon Contamination

Ayolabi¹,

Folorunso²,

Idem³

2012

ESR

Self Cite

View full text Add to dashboard Cite

The subsurface soil around Baruwa community was reportedly contaminated by hydrocarbon not because the area falls within oil-producing community but it suffers from inceasant leakage from petroleum pipeline that supply petroleum products to hydrocarbon terminar located within the area. Thus, to ascretain the extent of contamination of the subsurface soil around the area, an integrated geophysical methods involving vertical electrical sounding (VES) and electrical resistivity tomography (ERT) supported with induced polarization (IP) and spontaneous potential (SP) methods were carried out. The hydrocarbon contaminated layers were marked out beneath each VES point by high resistivity ranging between 943Ωm and 4749Ωm at a depth of 1 to 35.44m below the surface. Similarly, ERT result shows that the subsurface soil around the investigated area has been contaminated at a shallow depth of about 2m downward with resistivity value above 1000Ωm. IP and SP data were Integrated to identify the sandy contaminated layers from clayey layer. IP value of 0 to 10mV/V and SP values of <+10mV were obtained over the sandy formation. The work shows that hydrocarbon leaking from the pipeline laid a few meters beneath the earth surface actually flow both upwardly (possibly due to seasonal variation in the water table which is usually close to the surface during rainy season) to the surface and downwardly at greater depth into the subsurface, through a porous medium -sandy layer. This may probably accounts for the reason while most of the handdug wells in the area are reportedly contaminated with hydrocarbon products.

show abstract

Section: Electrical Resistivity Tomography (Ert) Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Application of Electrical Resistivity Tomography in Mapping Subsurface Hydrocarbon Contamination

Ayolabi¹,

Folorunso²,

Idem³

2012

ESR

Self Cite

View full text Add to dashboard Cite

show abstract

“…It appeared the area is a region of subsidence compare with the adjoining Lagos landmass and thus, it is an active water flooding zone (Ayolabi et al, 2010). The area is well vegetated with grasses, reeds and other plants that are peculiar to swamp or water lodged regions.…”

Section: The Study Areamentioning

confidence: 99%

“…The total length of the array is limited by space constrain to 252 m, hence the smallest electrode spacing of 4m using gradient electrode configuration was used. IP tomography was acquired alongside the ERT using the same electrode array with the same equipment according to standard practice (Murali & Patangay, 2006;Ayolabi et al, 2010). In all, a total of five 2-D profiles, parallel to each other at an interval of 10 m, were occupied for both ERT and IPT (Figure 1).…”

Section: -D Electrical Resistivity and Ip Tomographymentioning

confidence: 99%

“…Among the commonly employed geophysical methods to compliment geotechnical data are electrical resistivity, seismic refraction, GPR and VLF-EM (Roth, Nyquist, & Guzas, 2000;Schoor, 2002;Elawadi, El-Qady, Nigm, Shaaban, & Ushijima, 2006;Owusu-Nimo & Boadu, 2010;Folorunso, Ayolabi, Ariyo, & Oyebanji, 2012). These methods are deployed to obtain necessary information from the subsurface such as soil lithology, depth to bedrock, location and orientation of buried fractures, faults, abandoned river channels and detection of compressible soil layer (clay/peat) buried beneath the surface (Reynolds, 1997;Ayolabi et al, 2009;Ayolabi, Folorunso, & Oloruntola, 2010).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Engineering Site Characterisation Using 2-D and 3-D Electrical Resistivity Tomography

Ayolabi¹,

Enoh²,

Folorunso³

2012

ESR

Self Cite

View full text Add to dashboard Cite

Land reclaimed from water bodies or its equivalent (swamp, flood zones and abandon river channel) usually contain certain mechanically unstable geological formations (e.g. peat and clay) which are inimical to the foundation of engineering structures. Concerted effort must therefore be ensured to determine depth to competent layer across the proposed site as against conventional geotechnical test which is a point test.Complementary non invasive geophysical methods must be carried out for any engineering construction so as to ensure stability of building construction and avoid the devastating effects of building collapse rampant of late. Thus, electrical resistivity tomography and induced polarisation methods, constrained by percussion drilling, were used for the present study. The results of the 2-D and 3-D DC resistivity tomography using 64 multi-electrode systems with gradient electrode configuration along five parallel profiles with smallest electrode separation of 4.0m on a total length of 252 m was interpreted using Earth Imager Inversion software. The subsurface was characterised by Peat/Clay sandwich between upper and lower Clayey-sand/Sandy-clay and Sand. The presence of Peat and Clay were correlated to the cause of chronic differential settlements of some engineering structures within the area. The depths to the sand material were observed between 17-47 m. At shallow depths, the sand materials were underlain by mobile clay/peat materials, which correlates with the depth to competent layer (Sand) achieved by percussion drilling in the range of 20-24 m. This lithological sequence in which the near surface sand deposits are underlain by clay/peat saturated with water, gives a sense of instability to the overlaying sandy layer. To buttress this finding, residential and other public buildings surveyed in the entire area are marked with various degrees of distress, ranging from multiple cracks, sinking of building, partial collapse to complete collapse. It should be noted that the depth to the sand layer achieved during the research varied along the respective profiles. Thus application of 2-D resistivity tomography has revealed both the lateral and vertical variation in depth to competent sand layer within the study area as opposed to point information from CPT or Percussion drilling. This provides a useful guide to the site engineers in designing appropriate foundation structure.

show abstract

Geoelectric investigation to delineate groundwater potential and recharge zones in Suki river basin, north Maharashtra

et al. 2015

View full text Add to dashboard Cite

Constraining Causes of Structural Failure Using Electrical Resistivty Tomography (ERT): A Case Study of Lagos, Southwestern, Nigeria

Cited by 8 publications

References 8 publications

Application of Electrical Resistivity Tomography in Mapping Subsurface Hydrocarbon Contamination

Application of Electrical Resistivity Tomography in Mapping Subsurface Hydrocarbon Contamination

Engineering Site Characterisation Using 2-D and 3-D Electrical Resistivity Tomography

Geoelectric investigation to delineate groundwater potential and recharge zones in Suki river basin, north Maharashtra

Contact Info

Product

Resources

About