Longwall top coal fall index from an integrated numerical and statistical analysis

Assessment of top coal fall potential is great importance for sustainable longwall caving mining. However, available assessment tools/indices the are applicable to roof rock only, and their use (whose geological structures may be different) can inappropriate. This paper presents a new index in mining where controlled by cantilever effect. The developed from an integrated numerical statistical analysis using database Ha Lam mine Vietnam. reveals that strength stiffness in-seam discrete fractures coal’s elastic modulus inversely proportional fall. Meanwhile, density seam depth found directly A procedure development equation established single multiple regressions model transformation technique. named Fall Index (FI) proposed, taking modulus, fracture density, friction angle, as input parameters. study also statistically has most significant effect while show least on At same time, play similar roles results this assist engineers better assessing subsequently controlling stability various conditions design.