Skip to main content

Effect of IGS baseline length on GNSS Positioning Accuracy

Research Authors
Tarek Abdelsamea, Mohamed A Yousef, Mustafa K Alemam, Yasser G Mostafa
Research Date
Research Journal
Rudarsko-geološko-naftni zbornik
Research Pages
81-93
Research Vol
38
Research Year
2023

Seepage behaviour through earth dams with zones of different filling materials

Research Abstract

Since more than one-third of dam failures have been attributed to uncontrolled seepage, it is of great importance to investigate the behaviour of this phenomenon in order to achieve the maximum degree of safety for such dams. The present work investigated the influence of the permeability coefficient of the different materials used in zoned earth dams on different seepage parameters. For the modelling and analysis processes, the Seep/w and Seep2D software were employed. The numerical results prove that the optimum relative hydraulic conductivity between the inner and transition shells is about 0.001, and it is better to use filling materials with less hydraulic conductivity in the upstream transition and outer shells than in the downstream ones. A good agreement was noted between the obtained results from Seep/w and those from Seep2D. Reducing the hydraulic conductivity of both the upstream and the downstream shells, or of the downstream shells only, causes the pore water pressure in the dam body to increase significantly, and causes a remarkable reduction in the seeped water quantity and velocity. A moderate reduction in the different seepage parameters is achieved by reducing the hydraulic conductivity of the upstream transition shell, and a small reduction is noticed by reducing the hydraulic conductivity of the upstream outer shell.

Research Authors
Mahmoud M. Mostafa, Shen Zhenzhong
Research Date
Research Department
Research Journal
Water SA
Research Member
Research Pages
106-120
Research Publisher
Water Research Commission
Research Rank
Q4 (1.2)
Research Vol
50
Research Website
10.17159/wsa/2024.v50.i1.4055
Research Year
2024

Numerical study concerning the different drainage systems in earth dams

Research Abstract

One of the most popular tools for dealing with the seepage problem in embankment dams is using different types and shapes of downstream drains. So, the paper presents a comprehensive study of the different drainage systems through such dams. Many earth dam models are investigated through the SEEP/W model representing different dimensions and geometry of downstream drains. A comparison is carried out between the present study and previous experimental and numerical studies and the results of the present study are almost close to the previous studies. The present work concludes that the most influential factor in a horizontal drain is the length, and the thickness has a negligible effect. The reasonable length ratio of a horizontal drain (L/B) is about 0.34 according to the minimum seepage. The angle of toe drains has a slight effect on the different seepage parameters. The performance of the inclined chimney drain is better than the vertical drain to control the seepage.

Research Authors
Mahmoud M. Mostafa, Shen Zhenzhong
Research Date
Research Department
Research Journal
Journal of Hydraulic Structures
Research Member
Research Pages
101-117
Research Publisher
Shahid Chamran University of Ahvaz
Research Vol
9
Research Website
10.22055/jhs.2023.44272.1258
Research Year
2023

Effect of zones' dimensions and geometry on seepage through zoned earth dams

Research Abstract

The seepage study through earth dams is very essential for the design and construction processes of such dams to ensure the needed safety and efficient performance. The present study focuses on the seepage flow through zoned embankment dams by introducing a numerical analysis using the Seep/w numerical model. The main objective of the study is to investigate the different effects of the dam zones' thickness and side slopes on seepage through such dams to achieve the most suitable dimensions and geometry of the different zones. First, the Seep/w is used to analyze the problem of seepage through earth dams with an internal core. The present obtained results and the results of other previous experimental and analytical studies are almost close to each other. The present work proves that the best relative thickness of the inner, transition, and outer zones (t1:t2:t3) according to the minimum seepage and cost of the used materials is 2:1.5:1.5 respectively. At the same time, it is proven that the reasonable optimum side slopes (H:V) of the inner, transition, and outer zones are 1:1.75, 1.25:1, and 3.75:1 respectively.

Research Authors
Mahmoud M. Mostafa, Shen Zhenzhong
Research Date
Research Department
Research Journal
Journal of Engineering and Applied Science
Research Member
Research Pages
1-24
Research Publisher
SpringerOpen
Research Vol
70
Research Website
10.1186/s44147-023-00223-7
Research Year
2023

Novel design of thermo-electric air conditioning system integrated with PV panel for electric vehicles: Performance evaluation

Research Authors
Hossam A. Ahmed, Tamer F Megahed, Shinsuke Mori, Sameh Nada, Hamdy Hassan
Research Date
Research Journal
Applied Energy
Research Publisher
Elsevier
Research Vol
349
Research Year
2023

Performance investigation of new design thermoelectric air conditioning system for electric vehicles

Research Authors
Hossam A. Ahmed, Tamer F Megahed, Shinsuke Mori, Sameh Nada, Hamdy Hassan
Research Date
Research Journal
International Journal of Thermal Sciences
Research Publisher
Elsevier
Research Vol
191
Research Year
2023

Mapping Leachate Pathways in Aging Mining Tailings Pond Using Electrical Resistivity Tomography

Research Abstract

Mining activities often leave behind a legacy of environmental challenges, with aging tailings ponds representing a significant concern due to their potential for leachate formation and subsequent contaminant release. Thus, this study employs Electrical Resistivity Tomography (ERT) to investigate the intricate pathways of leachate within an aging mining tailings pond, addressing the pressing environmental and human health concerns associated with potential contaminant release. Ten 2D ERT profiles were acquired at the El Mochito mine waste site, covering an area of approximately half a square kilometer. These profiles, ranging in length from 104 to 363 m, provided insights into subsurface conditions down to a maximum depth of 60 m. The subsurface mapping of the ERT data showed three different geoelectric layers. The uppermost layer, with a thickness of approximately 2.5 m and resistivity values ranging from 60 to 100 Ohm.m, was identified as a dry tailing/soil zone. Beneath it, the second layer exhibited moderately resistive values (30–60 Ohm.m) with varying thicknesses of 10–20 m, signifying a percolation/leaching zone (semi-saturated zone). The third layer, characterized by substantially low resistivity (1–30 Ohm.m), indicated saturation and the presence of conductive materials, strongly suggesting active leaching. Based on these findings, this study recommends further investigation through geochemical analysis of subsurface samples and more advanced geophysical imaging techniques to validate the distribution of anomalous zones and delineate remediation pathways. This study lays the foundation for future comprehensive research that will integrate geophysical surveys with geochemical analysis and establish 4D modeling techniques to monitor pollutant penetration over time, with a particular focus on mine waste tailings mapping. Plus, this study contributes valuable insights into the characterization of leachate pathways within mining tailings ponds, offering a foundation for informed environmental management and remediation strategies.

Research Authors
Mosaad Ali Hussein Ali, Farag M Mewafy, Wei Qian, Fahad Alshehri, Sattam Almadani, Mofleh Aldawsri, Majed Aloufi, Hussein A Saleem
Research Date
Research Journal
Minerals
Research Member
Research Pages
1437 (19)
Research Publisher
MDPI
Research Rank
International Journal (Q2)
Research Vol
13
Research Website
https://www.mdpi.com/2075-163X/13/11/1437
Research Year
2023

Integration of Electrical Resistivity Tomography and Induced Polarization for Characterization and Mapping of (Pb-Zn-Ag) Sulfide Deposits

Research Abstract

The accurate characterization and mapping of low-grade ore deposits necessitate the utilization of a robust exploration technique. Induced polarization (IP) tomography is a powerful geophysical method for mineral exploration. An integrated survey using electrical resistivity tomography (ERT) and IP was employed in this study to characterize and map (Zn-Pb-Ag) ore deposits in NE New Brunswick, Canada. The survey encompassed twelve parallel lines across the study area. The 2D and 3D inversion of the results provided a detailed image of the resistivity and chargeability ranges of subsurface formations. The boundaries of sulfide mineralization were determined based on resistivity values of (700–2000 Ohm.m) and chargeability values of (3.5 mV/V) and were found to be located at an approximate depth of 80–150 m from the surface. The findings were validated through a comparison with data from borehole logs and mineralogy data analysis. The size and shape of sulfide deposits were successfully characterized and mapped in the study area using this cost-effective mapping approach.

Research Authors
Mosaad Ali Hussein Ali, Farag M Mewafy, Wei Qian, Fahad Alshehri, Mohamed S Ahmed, Hussein A Saleem
Research Date
Research Journal
Minerals
Research Member
Research Pages
986(19)
Research Publisher
MDPI
Research Rank
International Journal (Q2)
Research Vol
13
Research Website
https://www.mdpi.com/2075-163X/13/7/986
Research Year
2023
Subscribe to