Performance evaluation of asphalt concrete core earth-rock fill dam relative to clay core earth-rock fill dam in the case of Megech Dam, Ethiopia

• Published in: Arabian journal of geosciences Vol. 14; no. 24
• Main Authors: Alemie, Neway Asrat, Wosenie, Mekete Dessie, Belew, Amanuel Zewdu, Kibret, Eshetu Adane, Ayele, Workineh Tadesse
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.12.2021; Springer Nature B.V
• Subjects: Asphalt; Asphaltic concrete; Clay; Concrete; Concrete dams; Control stability; Dam design; Dam engineering; Dam stability; Dams; Deformation; Deformation analysis; Design; Downstream effects; Earth; Earth and Environmental Science; Earth science; Earth Sciences; Economic analysis; Embankment dams; Embankments; Original Paper; Performance evaluation; Rockfill dams; Rocks; Safety factors; Seepage control; Slope stability; Stability analysis; Weather; Asphalt; Slope/W; Seep/W; Sigma/W; Clay core
• ISSN: 1866-7511; 1866-7538
• DOI: 10.1007/s12517-021-09009-8

Seepage control is one of the important requirements in the design of embankment dams. This requirement can be accomplished by using different materials as the core of the dam like asphaltic concrete, geomembranes, and clay cores. This study is aimed at evaluating the performance of asphalt concrete and clay as core materials, mainly from the efficiency of seepage control, stability conditions under different loading conditions, and stress-deformation in the case of Megech earth-rock fill dam. Geo - studio 2012 model was employed to conduct the seepage, stability, and deformation analysis of the dam. The result of the SEEP/W module of the Geo-studio 12 model shows that the total flow per unit length through the dam body and foundation for asphalt concrete core at full reservoir condition is 9.95 × 10 −6 m 3 /s, and for clay core, the result is 1.689 × 10 −5 m 3 /s. The result indicates that asphalt concrete core dams have better performance than clay core dams in controlling seepage. Using the limit equilibrium and Morgenstern-Price method of slope stability analysis, the SLOPE/W analysis results during steady-state for the upstream slope show a factor of safety of 1.520 for clay core dam and 1.801 for asphalt concrete core dam. Similarly, for the same loading condition as above, the factor of safety obtained is 1.503 and 1.797, respectively for the downstream slope. The results show that asphalt concrete core provisions maintain better stability than clay core provisions for the same loading and material conditions. Moreover, the economic analysis study result shows that the asphalt concrete core dam design option is more economical than the clay core due to the reduced construction time of the dam, as it is not affected by weather conditions.