A Case Study on Coal Pit & Dump Slope Stability of Gondudih Khas Kusunda Open Cast Project of Kusunda Area of BCCL, Dhanbad

Abstract

Slope stability is a critical aspect of open-cast mining to ensure safe and productive operations. Poor slope design can lead to slope failures, risking worker safety, damaging equipment, and causing production delays. This study evaluates the stability of pit and dump slopes at the Gondudih Khas Kusunda Open-Cast Project (GKK OCP) in the Kusunda Area of Bharat Coking Coal Limited (BCCL), located in Dhanbad, Jharkhand. The main aim is to assess current slope designs, identify potential risks, and suggest improvements that balance safety, efficiency, and cost.The GKK OCP lies in the eastern part of the Jharia coalfield, with terrain gently sloping between 207 and 219 meters above sea level. The region experiences a sub-humid tropical climate with annual rainfall between 1,200 and 1,380 mm. The mine site is geologically part of the Barakar Formation, underlain by Talcher strata.Fieldwork was conducted at eight representative points, and soil samples were collected at depths of 0.6–0.9 meters. Laboratory tests, including the core-cutter method and triaxial testing, were used to determine properties such as bulk density, dry density, cohesion, and angle of internal friction. These parameters were then analyzed using FLAC/Slope software to calculate the Factor of Safety (FOS) under different slope conditions.
Results showed that FOS decreases with increased bench height and slope angle but improves with greater bench width. The study recommends optimized bench parameters for pits: 10 m height, 12 m width, and 60° slope angle. Controlled blasting is also advised to reduce vibration and improve slope integrity. These findings meet DGMS guidelines and offer a safer design for future mining operations.