Slope stability analysis of Nkran Pit at Asanko Gold Mine, Ghana

Abstract

The West Wall of Nkran Pit Mine is vulnerable to slope instability, mostly due to mining activities.Detailed failure analysis of the discontinuity data of the selected slope was performed using the Dips (6.0) software. The study has shown the likelihood of planar failure, wedge failure, flexural toppling failure and direct toppling failure occurring per the slope angle design of 70°. When the slope angle was increased by 5° and 10°, there were percentage increases in planar, wedge, flexural toppling and direct toppling failure of (1.86 and 7.45)%, (1.23 and 2.81)%, (0.62 and 0.62)% and (0.60 and 1.70)% respectively. It has been recommended that flattening or reducing slope angle could be done as it reduces the weight of material which in turn improves the stability of the slope and also controlled blasting should be employed to minimise excessive damage to the walls.

Slope angle estimation of Amoanda East Pit of Abosso Gold Fields, Ghana

“…Kinematic analysis is a method used to analyse the potential for the various modes of slope failures that occur due to the presence of unfavorable oriented discontinuities. Analysis of the Amoanda East wall was assessed using DIPS 6.0 to determine the possible modes of failure that can occur and the possibility and effect of increasing the East slope wall angle by 5 o and 10 o from 70 o taking into consideration the procedures proposed by [14] for similar geomechanical conditions at Nkran Pit of Asanco Gold where the slope angle was increased by 5° and 10°.…”

Geotechnical Assessment of Rock Slope Stability Using Kinematic and Limit Equilibrium Analysis for Safety Evaluation

“…Landslides mainly occur on dip slopes and sporadically happen elsewhere [14]. In addition, it is possible to decrease the slope angle because doing so lowers the weight of the material, enhancing the slopes' stability [1]. From the kinematic analysis result of the right bank, it can be seen that toppling failure probabilities are slightly more than 5% when the slope dip angle is 40 • , but they gradually increase as the slope dip angle increases, obtaining a maximum of 5.5% at a dip angle of 55 • .…”

“…Especially in steep and mountainous regions, rock slopes are one of the most critical concerns in road construction. Distinct rock mass conditions, different discontinuities, shear zones, faults, thrusts, an unprofessional method of slope cutting, excessive rainfall, seismic activity, and tectonic activities make slopes more susceptible to instability problems [1][2][3][4]. Nevertheless, the most frequent types of slope failure are planar, wedge, rock topples, and rockfalls [5].…”