The topic of underground excavation in weak rock mass for civil applications is well analyzed and studied by researchers and engineers. However, limited studies are available for weak ground conditions in underground mining environments. Most rock engineering and rock mass classification systems were developed based on tunneling and civil applications of rock, soil mechanics and case histories. The current challenges faced by many underground mine operators working on excavations in poor ground are to ensure a safe working environment, maintain stability of the underground infrastructure, preserve mineable reserves, and to perform this economically. This paper provides a summary and perspectives on the application of commonly used ground support systems updated with information on Thin Spray on Liners to address weak rock mass conditions for underground mines based on a practical engineering approach.
The increase in rock mechanics understanding, evolution in ground support systems and computing technology when integrated with practical experience enables engineers to design safer underground excavations in weak rock mass. The focus of this paper is to promote discussion on the practical aspects of the utilization of modern rock support types in underground metalliferous mines to address weak rock mass conditions. This paper is an updated version of the authors' earlier publications with the introduction to Thin Spray on Liners which is currently gaining the attention of mining operators (Foo et. al, 2010). The objectives of rock mechanics are to ensure the overall stability of the mine structure and safety of the working area, and preserve the condition of ore reserve for mining (Brady and Brown, 1993). Rock support and reinforcement systems are not the only elements enabling underground excavations to meet these objectives. Rock supports are commonly installed in stages within an excavation to achieve controlled ground displacement equilibrium.
