Evaluation of Carbonate and Heterogenous Rock Masses for the Dam Foundation: A Case Study at Kanarwe River Basin, Sulaimaniyah, NE Iraq

Evaluating rock masses for dam foundations, especially heterogeneous (flysch), becomes imperative and requires accurate geomechanical classifications. The rocks at the Kanarwe river basin, a proposed site (Goma-Qazan near Khewata, Sura Qalat villages), mainly consist of interlaying massive carbonate Aqra Formation with flysch Tanjero Formation. Therefore, selecting appropriate types is challenging very risky. This study conducted detailed lithology, discontinuity condition, sampling laboratory tests to determine suitable construction using quantitative GSI, Rock Mass Rating, Dam Rating classification systems. A new procedure was suggested calculating stress relaxation damage level (disturbance factor D) in masses. mass rating related foundation stability shows good indication ranging from 43.7–82.9, indicating suitability all types. excavation desirability consolidation grouting were evaluated based on dry basic rating, which that earth fill hardfill dams. However, units require spot systematic gravity Arch dams, respectively. Ec/Em (deformation modulus dam/deformation rocks) values range 0.18–0.93; they indicate arch, dam, While 1–6.4, some have serious problem situation need treatment