Geo-Electric Assessment of Kali Failed Dam Project Aliero, North Western Nigeria
Loading...
Date
2020-08-27
Journal Title
Journal ISSN
Volume Title
Publisher
International Journal of Geosciences
Abstract
An integrated geophysical investigation using very low frequency electro
magnetic (VLF-EM) and electrical resistivity methods using (VES) technique
has been carried out for investigation of possible causes of dam failure in Kali,
Aliero Northwestern Nigeria. A total of Three 3 (VLF-EM) traverses and Ten
10 vertical electrical soundings (VES) techniques have been carried out to
identify the fracture zones, seepage and possible threat that lead to the col
lapse of the dam. The interpretation of VLF-EM data is carried out qualita
tively using Fraser and Karous-Hjelt filters and the interpretation of sounding
data is done using IPI2 win software. VLF-EM data signifies the exact fracture
zones founded on higher values of relative current density that coincide to the
subsurface fracture. The survey was conducted on an interval of 10 m interval
along traverses at South-North direction ranging from 620 - 640 m in length.
The plot of filtered real and filtered imaginary identified noticeable fracture
zone close to the surface which was later further delineated by (VES) tech
nique. VES soundings were carried out at locations of prominent VLF ano
malies presumably typical of basement fracture using AB/2 of 80 m. Results
interpreted show layers thickness and their corresponding resistivity, top soil
(0.5 m to 3.45 m, 51.9 Ωm to 318 Ωm), underlain by clay to confined clay
(4.56 m to 54 m, 7.88 Ωm to 60.2 Ωm) which is underlain by fractured/fresh
basement (5.76 m to 73.9 m, 40.3 Ωm to 197 Ωm). The overburden materials
underlain are far away to subsurface (bed rock) in most of the area to support
the dam. The clay materials which could serve as conduit, exist within the
shallow overburden which was not excavated during the construction.
Therefore it was concluded that the dam cannot retain its strength to oppose
the dam against collapse.
Description
Keywords
Citation
5. Magawata, U.Z., Mohammed, I., Ojulari, B.A., Augie, A.I. and Musa, S. (2020) Geo- Electric Assessment of Kali Failed Dam Project Aliero, North Western Nigeria. International Journal of Geosciences, 11, 1-13. https://doi.org/10.4236/ijg.2020.111001