Authors : M.A.M. Ez Eldin , Tang Huiming , Li Changdong and A.G. Farwa
Abstract: This study presents the engineering geological assessment of sandstones from Jebel Aulia New Hydroelectric Power Plant (NHPP) site, situated at Jebel Aulia Dam, 50 km south of Khartoum; the capital of Sudan. This is the first time is thought over to make use of the dam in generating hydroelectric power. The study has been conducted by geological fieldwork and geophysical investigations (Vertical Electrical Sounding and Seismic Refraction), drilling, petrographic studies and laboratory testing of sandstone rock samples. The fine, medium and coarse-grained sandstones are cemented mainly by silica, kaolin, iron oxides, manganese oxides and calcium carbonate. The petrographic studies indicated that the sandstones are mainly composed of quartz, rock fragments, little feldspar (less than 5%) and micas. Accordingly, these sandstones can be classified as greywacke or quartz wacke based on Pettijohn’s definition. The fractures analyses of Jebel Aulia indicated that, they are probably tectonic in origin and were formed due to the effect of Jebel Aulia fault. The average hydraulic conductivity of the sandstones is interpreted as high with no significant vertical variation in the water level and seepage occurrence on the foundation. Generally, the degree of weathering and porosity decreases with increasing of depth and the values of the RQD, TCR, specific gravity, bulk density, UCS and point load strength test results increase with increasing of depth unless other conditions may disturb this sequence. The depth to the fine to medium-grained sandstone varies from about 2.5-10 m.
M.A.M. Ez Eldin , Tang Huiming , Li Changdong and A.G. Farwa , 2008. Engineering Geological Assessment of Sandstone Rock from Jebel Aulia New Hydroelectric Power Plant Site, Jebel Aulia Dam, Sudan. Journal of Engineering and Applied Sciences, 3: 109-117.