DEEP MINING PAPERS
Full-scale rockbolt testing in the laboratory: Analysis of recent results
By S.A. Hagen, T. Larsen, A. Berghorst, and G. Knox
Rockbolting is a method used for rock reinforcement in underground mining and tunnelling. A rockbolt test rig has been developed for full-scale testing for pull, shear, and combination pull-shear tests. This paper describes the principles behind this quasi-static, full-scale testing and includes the results and analyses of recent tests performed on different types of rockbolts.
A practical design approach for an improved resin-anchored tendon
By B.R. Crompton and J. Sheppard
The support strength of a resin-grouted tendon is often constrained by the resin annulus between the tendon and the borehole. This paper documents a practical investigation into the effectiveness of typical resin tendon designs in large annulus installations and the development of an improved tendon design for such cases.
Artificial intelligence and big data analytics in mining geomechanics
By J. McGaughey
A process and software framework is presented that solves the prerequisite 4D data integration problem, setting the stage for routine application of AI or machine learning methods in mining geomechanics. The system rationale and structure are described with reference to specific AI challenges in rock engineering.
The need for improved layout design criteria for deep tabular stopes
By Y. Jooste and D.F. Malan
Aspects related to two popular design criteria used in the deep gold mines of South Africa, i.e. average pillar stress (APS) and energy release rate (ERR), are described. A numerical modelling study is presented that illustrates the effect of total closure on the simulated APS and ERR values of remnants. It is recommended that stress measurements be conducted below remnant areas to better calibrate the numerical models.
The geotechnical evolution of deep-level mechanized destress mining at South Deep mine
By P.G. Andrews, R.J. Butcher, and J. Ekkerd
The main geotechnical challenges for successfully mining the South Deep orebody were to introduce a mechanized mining method to destress and then cost-effectively extract the massive, low-grade orebody. This paper outlines the geotechnical processes used to overcome issues including ground support, seismicity, and rock mass conditions, and highlights the key leanings from a deep-level massive mine's evolution over time.
The role of rock mass heterogeneity and buckling mechanisms in excavation performance in foliated ground at Westwood Mine, Quebec
By L. Bouzeran, M. Pierce, P. Andrieux, and E. Williams
Operations at Westwood mine in Quebec, Canada were temporarily halted in May 2015 after three large-magnitude seismic events occurred over two days. Geotechnical characterization of the rock mass was carried out and numerical back-analyses of several locations were completed. The objectives of the back-analyses were to better understand the mechanisms controlling rock mass performance and to obtain a calibrated model for predictive stoping simulations.
Applications for the Hovermap autonomous drone system in underground mining operations
By E. Jones, J. Sofonia, C. Canales, S. Hrabar, and F. Kendoul
This paper discusses the development and current state of the Hovermap autonomous drone system in underground mines and areas inaccessible to GPS instrumentation. The examples focus principally on improving safety through a better understanding of the rock mass behaviour and failure mechanisms.
Anisotropic rock mass behaviour in high-displacement ground at CSA mine
By G.B. Sharrock and B. Chapula
This paper summarizes key findings from a 39-month study at CSA mine on factors controlling anisotropic ground behaviour. The aim was to understand factors controlling high-displacement ground behaviour. The stress path induced by mining was found to significantly affect both the initiation and progression of damage in both tunnels and raises.
Addressing misconceptions regarding seismic hazard assessment in mines: b-value, Mmax, and space-time normalization
By J. Wesseloo
Some misconceptions with respect to seismic hazard assessment appear to be present in the industry. Where these misconceptions exist, they adversely affect the quality of seismic hazard assessment and risk management decision-making. This paper address some of these misconceptions.
Do stopes contribute to the seismic source
By L.M. Linzer, M.W. Hildyard, S.M. Spottiswoode, and J. Wesseloo
An investigation was undertaken on the influence of the stope on seismic inversions for the scalar moment, corner frequency/source radius, and stress drop through numerical modelling using WAVE3D. The results show that the stope appears to have an appreciable effect on the seismic inversions.
Development of a remote-controlled rockbolting system for narrow-seam hard-rock mines
By D.M. O'Connor and T. Sertic
This paper describes the development of a semi-automated, remotely-controlled rockbolting system for use in hard rock mines with a mining height of between 0.9 m and 1.2 m (the ULP Project). The introduction of systematic rockbolting has resulted in a decrease in rockfall-related accidents.
