Ground support forms an integral part of underground mines to maintain stable excavations, sustain productivity, and most importantly, provide a safe working environment. The support designs are generally based on the support capacity, dimensions and pattern. The support capacity is based on manufacturers’ specifications and published documentation. In other cases, support standards from similar operations are adopted with the expectation that these will provide the required support. While some testing might be conducted during the implementation, practices from other operations frequently form the basis for the specifications and procedures. Once support requirements are defined, the support installation process often becomes a routine task. Over time, less attention is paid to the controls required to achieve the designed support capacity. Routine testing is often infrequent, and testing is more likely to be focused on changes in ground support products. Qualitative visual assessments become the primary method of quality assurance.
SRK evaluated, planned and provided continuous support during the implementation of an underground rehabilitation project. The margin for error was minimal, and it was critical that the ground support was installed and functioned as expected. The criticality of the project justified a level of detail which is not common in mining projects. Under SRK’s supervision, the contractor performed a battery of tests prior to commissioning and during execution of the project. Stringent quality control measures identified deficiencies in product selection, equipment setup and the installation procedure. It was evident that support product selection based on suppliers’ specification with limited consideration of other contributing factors is inadequate. Although support installation and application procedures adopted from similar operations provide a basis, the implementation process should consider the potential differences.
This project highlighted various potential pitfalls when blindly specifying support products and adopting the “standard” installation methods. The site-specific support trials, routine testing, and continuous quality assurance proved critical to the identification of substandard support and successful execution of the project.
