Optimization of cable bolting pattern for cut-and-fill slopes in a manganese mine using observational, empirical, and numerical modelling approaches

摘要

Results of scientific investigations on the optimization of the rock reinforcement system (cable bolting) at Chikla Mine, MOIL, India, are presented in this paper. The mine is implementing a systematic roof support program that primarily contains cable bolting in a 2.0 m square grid pattern. The fully grouted cables are 16 mm in diameter and 12 m in length. Additionally, 20 mm diameter, 1.5 m long, full column grouted rock bolts in the centre of the cable bolting grid are also implemented for the manganese orebody with widths ranging from 9 to 24 m (average width 12 m) and a dip angle of 55 deg to 90 deg. Manganese ore mineralization, primarily in the form of braunite and gondite minerals, is flanked by mus-covite schist/quartz muscovite, and schist in Chikla Mine, MOIL. The depth of workings is in between 40 and 70 m from the surface, and a cut-and-fill stoping operation is being practiced to produce average stope widths of 12 m. Field and laboratory investigations are carried out to obtain empirical rock mass classification parameters and input parameters for numerical modelling. The safety factor contouring method, using a failure criterion suggested by Sheorey (1997), is used for plain strain numerical modelling in a general purpose finite difference method-based numerical modelling code- FLAC3D.