Electrical resistivity imaging and engineering geological investigation of Gereb Segen dam, northern Ethiopia

Mebrahtu, Gebreslassie; Abay, Asmelash; Hailu, Gebrerufael; Hagos, Miruts

doi:10.1007/s10064-019-01577-0

Cited by 7 publications

(3 citation statements)

References 37 publications

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“…The injection grout generally contains water with a very small amount of cement, depending on the desired performance, bentonite, and loads. It must be sufficiently fluid to flow under pressure into the cracks of the rock up to the target volume where, after hardening, it must have the desired properties [13]. This grout, based on cement and water [14], may possibly contain mineral additions, adjuvants, and inert charge.…”

Section: B Formula Of the Injection Groutmentioning

confidence: 99%

Grout Curtain Construction at Tiddas Dam, Morocco

Tahar¹,

Bahi²,

Ouadif³

et al. 2022

Int. J. Adv. Sci. Eng. Inf. Technol.

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Dam foundations are generally affected by water leakage and seepage, posing a significant threat to the structure's safety. Such an artificial water reservoir unconditionally assumes a watertight foundation, as perfect as possible, to ensure its stability. This brings us back to thinking about an adequate treatment of the foundation through the injections of the grout curtain, which ensures the watertightness of the ground and a good drainage system, which together improve the unacceptable mechanical and hydraulic properties of the foundation. Our study focuses on the Tiddas Dam, a dam in the region of Khemisset located on the Bouregreg oued, intended to supply drinking and industrial water to the region of Rabat and Casablanca. It has been the subject of several geological and geophysical studies to characterize its foundation and the lithological variety known to the site. Environmental constraints and the development of a network of fractures and faults have made it necessary to think of an innovative solution for the waterproofing of the dam, especially on the right bank, ensured by a grout curtain of well-defined dimensions considering all the factors affecting this bank. The paper presents the particularities of the site, the constraints of the design of the grout curtain of a dam in a fractured environment, the choices of this design and the sizing methods used, as well as the appropriate grouting formula, which together could optimize the consistency of the grouting works.

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Section: B Formula Of the Injection Groutmentioning

confidence: 99%

Grout Curtain Construction at Tiddas Dam, Morocco

Tahar¹,

Bahi²,

Ouadif³

et al. 2022

Int. J. Adv. Sci. Eng. Inf. Technol.

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“…It is also possible to locate anomalous foundation features like dykes, cavities, fault zones and buried river channels [3]. Electrical resistivity technique, had been extensively used for a wide variety of engineering applications such as; dam site investigations, bridge and building structure foundations, seepage investigation, mapping of internal landfill structures, imaging faults, landslide investigations and imagining of engineered hydraulic barriers [2,[4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. VES is widely used to define the overburden thickness in geotechnical surveys and to delineate horizontal zones of porous strata in hydrogeology [19,20].…”

Section: Introductionmentioning

confidence: 99%

Application of Vertical Electrical Sounding for Study the Proposed dam site at Wadi Ma’doo, Shabwah Governorate, Yemen

2020

EESRR

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Application of geophysical investigation has been carried out using Vertical Electrical Sounding (VES) at the proposed site in wadi Ma’doo, Shabwah Governorate, Yemen to determine the geophysical parameters that can be used to evaluate the subsurface geological layering characteristics of the selection proposed site for dam construction. The Schlumberger array was used for the data acquisition. One-dimensional numerical inversion of individual DC resistivity was used to enhance the processing of the results for better achievement of the aim of the study. Model obtained from the 2D inversion of each VES were used for construction of geoelectric section which exhibit the main geoelectric characteristics of the geological units present in the site. The interpretation of the field data was carried out using the IP12WIN software, which converts the apparent resistivity as a function of electrode spacing to the true resistivity as a function of depth in two dimensions. The interpretation results showed that the geoelectric section consists of three layers namely: boulders and gravels, sandy to pebbly and hard limestone. The layer resistivities and thicknesses range from 18.17 to 746.20 Ω.m/0.20 to 1.084 m, 53 to 60 Ω.m/ 0.20 to 3.059 m and 455 to 1890 Ω.m, respectively. The investigation revealed that the limestone rocks is suitable for shallow foundation for proposed dam engineering structures.

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“…Karst caves are a hotspot in the research of engineering geology in karst regions [14,15]. Many prospecting geophysical prospecting methods have been widely adopted to explore the development of karst caves [16][17][18][19]. Fruitful results have been achieved on the evaluation of roof stability of karst caves [20,21], providing a good reference for the research into the stability of karst foundations [22,23].…”

Section: Introductionmentioning

confidence: 99%

Dissolution Features of Karst Foundations at Different Depth Sections

Cao¹,

Tang²,

Liu³

et al. 2020

IJDNE

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The dissolution of karst foundations can be divided into rock surface dissolution and hole dissolution. The dissolution features of karst foundations at different depths must be clearly identified before taking proper karst treatment measures. In this paper, more than 200 engineering data samples are collected from typical carbonate karstic regions in southwestern China, and 12 most representative engineering site were picked out. The rock surface dissolution ratio, hole dissolution ratio, and total dissolution ratio were measured at each engineering site, and used to fit the relationship between rock surface dissolution ratio and hole dissolution ratio at different depth sections. The results show that the karst foundation can be split into three sections from top to bottom: rock surface dissolution section Ⅰ, composite dissolution section Ⅱ, and hole dissolution section Ⅲ. The three sections occur inevitably as the rock surface dissolution occurs naturally from the inside. The dissolution degree decreases exponentially with the growing depth, and the rock surface dissolution ratio drops faster than the total dissolution ratio. Moreover, the hole dissolution ratio per unit volume of rock decreases with the increase of depth. If the holes are not developed, the engineering sites will only have rock surface dissolution section; if the holes become more developed, the composite dissolution section will expand gradually and dominate site dissolution. At most locations, the hole dissolution ratios under the minimum elevation of rock surface are within 10%. Finally, it is suggested that the final elevation of the drilling holes must be controlled above the minimum elevation of rock surface. The research results shed new light on the mitigation of dissolution of karst foundations.

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Electrical resistivity imaging and engineering geological investigation of Gereb Segen dam, northern Ethiopia

Cited by 7 publications

References 37 publications

Grout Curtain Construction at Tiddas Dam, Morocco

Grout Curtain Construction at Tiddas Dam, Morocco

Application of Vertical Electrical Sounding for Study the Proposed dam site at Wadi Ma’doo, Shabwah Governorate, Yemen

Dissolution Features of Karst Foundations at Different Depth Sections

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