Sustainable Underground Mining Infrastructure (SDG 9): Multi-Parameter Tunnel Stability Assessment Using RMR and Finite Element Modeling

Abstract

The Tunnel stability is a critical aspect of underground mining development, particularly in geologically heterogeneous and groundwater-influenced environments. This study evaluates the stability of a planned main access tunnel at the Cibujang Mine Project, Indonesia, through the integration of Rock Mass Rating (RMR) classification and Finite Element Method (FEM) analysis. Geomechanical characterization indicates significant variability in rock mass quality, with RMR values ranging from very poor to good conditions. Numerical simulations reveal that tunnel stability is strongly controlled by lithological variability and groundwater saturation. Portal stability analysis identifies critical instability conditions with safety factors below acceptable design criteria, while tunnel simulations indicate that clay-rich and low-RMR zones exhibit the greatest instability potential, particularly at the lower sidewall. The consistency between RMR classification and FEM-derived stability assessments demonstrates the effectiveness of integrating empirical and numerical approaches for identifying critical zones and developing support recommendations. The proposed framework contributes to safer, more efficient, and sustainable underground infrastructure development, supporting Sustainable Development Goal 9 (SDG 9).