IJ
IJCRM
International Journal of Contemporary Research in Multidisciplinary
ISSN: 2583-7397
Open Access • Peer Reviewed
Impact Factor: 5.67

International Journal of Contemporary Research In Multidisciplinary, 2026;5(2):59-64

Study of Opencast Mine Stability Under Different Geotechnical Conditions

Author Name: Somnath Kumar Rishi;   Syed Sakib Ali;   Vivek Kumar;   Indrajit Prasad Sinha;   Samir Ansari;   Pawan Kumar;   Manish Kumar Das;   Baibhav Kumar Das;  

1. Assistant Professor, Department of Mining Engineering, Jharkhand Rai University, Ranchi, Jharkhand, India

2. Students, Department of Mining Engineering, Jharkhand Rai University, Ranchi, Jharkhand, India

3. Students, Department of Mining Engineering, Jharkhand Rai University, Ranchi, Jharkhand, India

4. Students, Department of Mining Engineering, Jharkhand Rai University, Ranchi, Jharkhand, India

5. Students, Department of Mining Engineering, Jharkhand Rai University, Ranchi, Jharkhand, India

6. Students, Department of Mining Engineering, Jharkhand Rai University, Ranchi, Jharkhand, India

7. Students, Department of Mining Engineering, Jharkhand Rai University, Ranchi, Jharkhand, India

8. Students, Department of Mining Engineering, Jharkhand Rai University, Ranchi, Jharkhand, India

Abstract

Slope stability analysis remains a pivotal requirement in the geotechnical design and safe exploitation of deep opencast mining operations (Hoek & Bray, 1981; Bieniawski, 1989). This paper presents a rigorous assessment of highwall and inter-ramp slope stability configurations under dynamic geo-environmental variables, focusing specifically on the structural domains of the Gevra Opencast Coal Mine (SECL), Chhattisgarh, India. Geotechnical characterisation was executed via structural mapping, rock core logging, and extensive laboratory evaluation to index the physical and mechanical rock mass behaviours. Three structural classification frameworks—Rock Mass Rating (RMR), Slope Mass Rating (SMR), and the Geological Strength Index (GSI)—were employed across eight distinct lithological domains to derive baseline parameters. Stability verifications were conducted through Limit Equilibrium Methods (LEM), including Bishop’s Simplified, Janbu’s Generalised, and Spencer’s formulations, and cross-examined using 2D Finite Element Methods (FEM) via Shear Strength Reduction (SSR) models. The deterministic evaluations indicate a severe drop in the factor of safety (FOS) from 1.48 under dry states to 1.12 under structural pore water saturation models (ru = 0.3), collapsing to an unstable 0.96 when pore-fluid

pressure achieves an absolute saturation coefficient of 0.4. Probabilistic evaluation via Monte Carlo simulations

demonstrated an unacceptable failure probability of 22.7% during monsoon cycles for the current 38° inter-ramp profile. Comparative case studies from Jayant and Singrauli mines are presented to validate structural compliance. Finally, operational remediations, including directional horizontal dewatering arrays, customized blasting thresholds, and a multi-tiered early-warning velocity tracking protocol, are established to secure extraction safety.

Keywords

Slope Stability, Opencast Mining, Limit Equilibrium Method, Shear Strength Reduction, Pore Water Pressure, Monte Carlo Simulation, Rock Mass Classification.