Effect of cable bolt on the stope stability and economy of narrow vein gold mine

Project Title:

Supervisor(s):

Dr Greg You

Contact person and email address:

A brief description of the project:

Narrow gold veins are normally steeply dipped in a shear zone or a fault. Cut and fill open stoping mining method is commonly used to extract gold ore. There exist two outstanding issues: the instability of the hanging wall of the mining stope and the high dilution rate. For example, in a South African gold mine, the dilution ranged from 20% to 40% with the highest of 73% when the stope was coupled with major overbreak (Le Roux and Stacey (2015). This is a significant issue of mining economy, as well as an issue of stope stability.

Cable bolts are commonly used to reinforce the hanging wall of stopes. The purpose of this study is to enhance the performance of cable bolts in hang wall reinforcement in a gold mine so as to increase the stope stability and to reduce dilution in narrow vein gold mining. Fibre Bragg grating (FBG) sensors has been using to monitor structures with high reliability and accuracy. The diminutive FBG sensors can be easily embedded inside and in the interfaces of the structure to monitor strain development without affecting the structural integrity. This study consists of field investigation and numerical simulation. In the field investigation, FBG sensors are attached on the surface of cable at designated locations to investigate the integrity and shear strain propagation along the structural interfaces of cable bolt under the effect of dynamic load from mining blasting. In numerical simulation, finite element method will be used to characterise the behaviour of cable bolt in narrow vein gold mining. As a result, it will optimise the stope operation through optimised designs (of stope dimensions, cable bolting, and drilling and blasting) and reduced dilution and mining cost.