DESIGN OPTIMIZATION AND SELECTION FRAMEWORK FOR INTEGRATED GROUND SUPPORT IN UNDERGROUND MINING: ROCK BOLTS, SHOTCRETE, AND HYBRID SYSTEMS

Mining Engineering

The design and selection of ground support systems for underground mining excavations represents one of the most geotechnically complex and economically consequential decisions faced by mining engineers. Rock bolting and shotcrete are the two principal ground support technologies in current practice, each with distinct mechanical mechanisms, performance envelopes, and economic profiles. While considerable individual literature exists on the design of each system, a unified framework for the integrated selection, design, and quality assurance of combined rock bolt-shotcrete support systems, keyed to rock mass classification parameters, remains lacking in the published literature. This paper addresses this gap by developing and presenting a systematic design optimization and selection framework for integrated ground support systems in underground coal and hard-rock mining environments. The framework is grounded in secondary research methodology, synthesising findings from peer-reviewed publications spanning 2008 to 2024, supplemented by foundational design references. The Q-system and Rock Mass Rating (RMR) frameworks are used as the primary classification tools to map geological conditions to support design categories. Within each category, the framework specifies: (i) recommended bolt type, length, spacing, and pattern; (ii) shotcrete type, thickness, and fibre dosage; (iii) supplementary support requirements; and (iv) quality assurance and monitoring requirements. Case studies from five major mining regions — Australia, South Africa, Canada, Scandinavia, and the United States — are examined to validate the framework against field-demonstrated outcomes. Special emphasis is placed on integrated support design for dynamic and seismically active environments, where the combined deployment of yielding rock bolts with steel-fibre-reinforced shotcrete (SFRS) has been demonstrated to provide significantly superior performance compared to either system individually. Design equations for bolt suspension load, bond strength, energy absorption, and Q-system equivalent dimension are presented and discussed. Practical recommendations for quality assurance, real-time monitoring, and durability design in aggressive underground environments are developed. The framework is intended to serve as a practical reference guide for mining engineers engaged in support design across a spectrum of geomechanical conditions.

This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.