Kinematic and Slope Mass Rating Application for Rock Slope Stability Evaluation Along Shanadar-Goratu Road in the Gali-Ashkafte Valley, Erbil, NE-Iraq

Abstract

A Study of rock slope stability along the Shanadar-Goratu main road, which is located near Mergasur town, northeast of Erbil city, is very necessary because many many slope failures take place every year, especially in the wet season. It is the main road between Erbil city and many towns and villages in the Mergasur district. For the current research, eight (8) rock-cut slope stations have been selected for 4.5 kms along the road from Shanadar to Goratu, based on differences in discontinuity pattern, slope geometry, and failure types. Field data has been assessed by the kinematic method, through DIPS v7.0 software, and by slope mass rating classification system, through SMRTool - v205 software. Kinematic analysis from DIPS v7.0 software showed that three types of failures (planar, wedge and toppling failures) may occur, and the largest susceptible rock masses to failure are of slope stations no. 1,5 and 8. In the worst conditions, the discrete-SMR and continuous-SMR pointed out that slope stations no. 1, 5 and 7 are completely unstable (class V – very bad slopes) with a failure possibility of 90%, while slope stations no. 2, 3 and 4 are unstable (class IV – bad slope) with failure possibility of 60%. However, slope stations no. 6 and 8 are partially stable (class III – normal slope face) with failure possibility of 40%, with an exception for slope station no.6 which is unstable (class IV – bad slope face) from continuous-SMR.