Investigating The Geological Engineering Site Of The Proposed Sabaloka Dam

Abstract

The proposed dam is located at the Sabaloka igneous complex on the sixth cataract of the Nile, where the Nile passes through the volcanic plateau of Sabaloka. The storage capacity of the proposed dam is about 4000 million cubic meters, its lake extends south to about 15 km, and the water level is expected to rise from 6 to 10 meters. The Sabaloka dam is proposed for multi-purposes, mainly for hydropower generation and irrigation in addition to helping minimize the siltation for the Merwe dam to the north. Moreover, it will represent an excellent habitant for fisheries in the lake behind the dam. The study relied on field tests, well data, and analysis, in addition to the structural analysis of fractures in the examined site. Observing the results of drilling, the three boreholes are usually identical in lithology, where silt sands and conglomerates appear, but there is some difference in the depth of aggregation, in addition to the difference in the designation of rock quality (RQD), which decreases in borehole 403 in the left channel, due to the existence of Two sets of joints across the dextral fault The proposed dam axis is located in the relatively less fractured Agglomeratic rocks. The main fracture trends are NW and NE directions and cut, respectively, the western and eastern flanks of the dam axis. Geotechnical tests on the area's rocks also proved the efficiency of the Trachybasalt and Suleik granite located in the Sabaloka area for use as concrete aggregate in construction according to the standard specifications.