Parametric study to design competent irregular-shaped remnants in mechanised depillaring


Mechanised depillaring (MD) has been proved to be a panacea for faster extraction of the developed pillars which is blocking access to deeper deposits and locking more than 3200 Mt of coal, developed by Bord and Pillar mining method in Indian coalfields. Depillaring of these square/rectangular-shaped developed pillars by continuous miner creates irregular-shaped ribs/snooks. Stability assessment of such ribs/snooks becomes a challenging task due to various issues faced in estimation of load acting upon it and their strength. Area-based approach for the design of rib/snook is found to be the most suitable criteria during MD. Field investigations supported for parametric investigation for a competent size of rib/snook with varying nature of roof and depth of cover. Taking help from previous studies to design such ribs/snooks on numerical models using FLAC3D, a parametric study is carried out using 3DEC. Strength of such ribs/snooks and load acting upon them is calculated with the help of calibrated numerical models in order to estimate their factor of safety. This paper presents a review of the previous researches and a novel numerical simulation technique for estimation of a competent size of rib/snook in a given geo-mining condition.

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The authors express their gratitude to the Directors of CSIR-CIMFR, IIT(ISM) Dhanbad, and IIT(BHU) Varanasi for their permission to publish this paper. This paper is a part of PhD work being carried out by Ashok Kumar who is the communicating author. The views expressed in the paper are those of the authors, and not necessarily of the institutes to which they belong. The cooperation provided by the management of different coal companies is thankfully acknowledged.

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Sharma, P., Kumar, A., Shams, N. et al. Parametric study to design competent irregular-shaped remnants in mechanised depillaring. Arab J Geosci 14, 247 (2021).

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  • Ribs/snooks
  • Mechanised depillaring
  • Stress-strain characteristics
  • Factor of safety
  • Numerical modelling
  • Area-based design