Advanced stability evaluation of underground marble quarry: a modelling and monitoring approach

Kumar, Mritunjay; Avchar, Akhil; Sinha, Shambhavi

doi:10.22059/ijmge.2026.407278.595342

Advanced stability evaluation of underground marble quarry: a modelling and monitoring approach

Articles in Press

Document Type : Research Paper

Authors

Mritunjay Kumar

Akhil Avchar

Shambhavi sinha

Department of Mining Engineering, NITK Surathkal, India.

10.22059/ijmge.2026.407278.595342

Abstract

This study evaluated the short-to-medium term static geomechanical stability of an underground marble quarry near Gujarat, India, using an integrated geomechanical approach combining FLAC3D numerical modeling, real-time in-situ stress monitoring, and empirical methods. The room-and-pillar system in a high-strength marble rock mass (GSI=72) intersected by a dolerite dyke was analyzed across varying overburden depths (57–87 m). Modeling confirmed pillar stability with stresses of 4.15–6.87 MPa and FOS consistently above 2.0. A 2-m-thick roof layer showed localized yielding, effectively controlled by 3.5-m-long, fully grouted Fe500D rockbolts (24 mm diameter, 2.2 m×2.2 m spacing), achieving FOS of 2.27–3.93 (resin grout: 3.93). In-situ monitoring recorded stress variations of 0.2–0.4 MPa, validating predictions and enabling back-analysis that refined the deformation modulus to 35 GPa for fractured marble. Monte Carlo simulations yielded a mean pillar FOS of 2.93 (95% CI: [2.21, 3.76]), with only 0.6% probability of FOS<2.0. The validated framework confirms short-to-medium term static geomechanical stability consistent with DGMS safety requirements, supports adaptive staged excavations near the dyke, and provides a replicable model for sustainable underground dimensional stone quarrying in complex geological settings.

Keywords

Room-and-pillar mining

Dolerite dyke

Rockbolts

In-situ monitoring

Monte Carlo simulation

Subjects