Critical assessment on challenges and advances in coal pillar strength estimation techniques: A focus on geological discontinuities

Abstract

Accurate estimation of coal pillar strength is essential for ensuring safety and operational efficiency in underground mining. Current assessment methods often face limitations in addressing time-dependent failure mechanisms, geological discontinuities, and dynamic loading conditions. This paper identifies future research directions aimed at enhancing the reliability of pillar strength evaluations. One important focus is the development of advanced numerical models that account for time-dependent behaviours such as creep and fatigue. Incorporating multi-scale modelling techniques, which connect micro-scale material responses to macro-scale structural performance, may lead to more precise predictions. The integration of real-time monitoring systems measuring stress, deformation, and environmental factors into predictive models can enable continuous assessment and proactive management. When combined with machine learning algorithms analysing large datasets and recognizing patterns, these approaches can optimize predictive accuracy and maintenance strategies. Improved geological characterization using advanced mapping technologies, such as geophysical surveys, is critical to account for weak planes, fractures, and faults. Additionally, long-term field monitoring and laboratory experiments are necessary to validate and refine models. Establishing standardized regulatory guidelines will help ensure consistency, particularly in challenging mining environments. Collaboration between academia and industry is essential to drive innovation and develop robust, reliable methods for coal pillar strength estimation.