Practical Estimates of Rock Mass Strength and Deformation Modulus: A Case Study of Gattar-V Uranium Occurrence, Arabo-African Shield

The primary objective of this paper is to categorize the quality of the rock mass in the Gattar-V uranium occurrence, which is a part of Gabal Gattar. This has been done by utilizing the Rock Mass Rating (RMR), Rock Mass Quality (Q), and Geological Strength Index (GSI). The results obtained from this classification are used to determine the most accurate estimates for current and future excavation and support systems. The results of the correlations between rock mass classification systems (RMR, Q, and GSI) indicate the followings: First, the support system recommended by the Q system is more effective in ensuring the stability of rock units in future tunnels. Second, the excavation of tunnels suggested by the RMR system is more efficient in ensuring the stability of rock units in future tunnels. Third, the current tunnel is stable and doesnt need supporting with a maximum unsupported tunnel span of 6.2 meters requiring no rock bolts or fiber-reinforced shotcrete. Fourth, for future tunnels with a span greater than 6.2 meters, the excavation and support system recommendations should be based on these rock mass classification results.