Assessment of Rock Slopes Stability Located on the Banks of the Khanas Dam Reservoir in the Nineveh Governorate, Northern Iraq.

A detailed study is conducted on the stability of the rock slopes at the two banks of the Khanas Dam reservoir located in the southeastern Sheikhan anticline, -Nineveh Governorate. The study includes seven stations distributed in both banks. The field survey is accomplished to determining the attitude of slopes and discontinuities of the rock blocks belonging to the Pilaspi Formation in the study area. The stability of the rock slopes is evaluated using Dips v: 6.008 program which uses kinematic analysis to predict potential structural failures (plane sliding, wedge sliding, flexure toppling and direct toppling), and SMARTool-v205 program used to determines the degree of the stability for each mode of failure. From the stability analysis results, it is found that there is possible occurrence of direct toppling at stations (SR1, SR2, SR3 and SL1), wedge sliding at stations (SR1, SR2, SR3, SL2 and SL3), flexural toppling at stations (SL1) and plane sliding at station (SR1). A program to evaluate the (slope mass rating shows the values of discrete (Slope Mass Rating SMR) and (Continuous Slope Mass Rating, (CSMR). At worst case, the lowest values for the slope mass rating of wedge sliding are in the stations (SR2 and SR3), where they range between (13-19) for discrete and (6-20) for continuous. While the highest wedge sliding values are in the stations (SL2 and SL3). In the discrete, they range between (44-46) and in continuous (CSMR), they range between (38-46). As for the direct toppling and in the worst condition in the spillway station, they are (44) in discrete and (48) in continuous, but the highest values are in the stations (SR2, SR3, SL1). They range between (51-61) in the discrete, and between (48-60) in continuous (CSMR), while the flexural toppling, is found at one station in (SL1) for the discrete (44) and continuous (47), and the plane sliding at the first station (SR1) for discrete status is (9), while in the continuous (CSMR) is (15)