Sahendra Ram
Council of Scientific and Industrial Research
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Publication
Featured researches published by Sahendra Ram.
Journal of The Geological Society of India | 2018
Ashok Kumar; Dheeraj Kumar; A. K. Verma; Arun Kumar Singh; Sahendra Ram; Rakesh Kumar
Depillaring of the existing pillars (square or rectangular in shape) by continuous miner provides irregular shaped ribs. An assessment of strength of such a rib becomes a difficult task. Literature review finds a number of approaches for the rib design but the scope of straight forward application of these approaches is limited due to the uniqueness of geo-mining conditions of the Indian coalfields. This review also finds that a wide spectrum of moderate roof conditions is yet to be properly addressed. Field studies at some depillaring operations in Indian coalfields indicated the influence of roof strata over the stability of a rib is considerably high. A systematic study of the roof strata influence on simulated models provided interesting results. A model for rib design is conceived on the basis of the simulation results. Discussing couple of field experiences of rib stability during mechanised depillaring under two different types of roof strata of Indian coalfields, this paper presents some results of the simulation along with the conceived model of a rib design.
Arabian Journal of Geosciences | 2017
Ashok Kumar; Rakesh Kumar; Arun Kumar Singh; Sahendra Ram; Pradeep Kumar Singh; Rajendra Singh
Underground extraction of total thickness of a thick coal seam in single lift by bord and pillar method increases pillar height during retreat. Field studies found that the increase in pillar height affects the depillaring operation adversely, especially, during caving of the strong/massive roof strata. Dilution in strength due to the increased pillar height caused catastrophic failure of barrier pillars and goaf overriding. This warrants a systematic study of pillar strength variation for the different heights of pillar. A review of different pillar strength estimation approaches for an analysis of the dilution in strength of the heightened pillar suggested that numerical modelling provides a better option for such a systematic study. Accordingly, investigations are conducted on simulated models in laboratory adopting a recognised numerical modelling procedure. The observed nature of variations in pillar strengths with the increase in its height in the numerical models and empirical formula is found to be matched. But a mismatch is found between the strength values of the two approaches with an increase in height of the pillar. Considering validity of the empirical formulation in Indian coalfields, a relationship is developed to incorporate a correction in the strength values of the numerical models. The suggested correction on the basis of this simple study of the pillar strength variation would be helpful for the use of the established simulation tool during the depillaring of a thick coal seam.
International Journal of Rock Mechanics and Mining Sciences | 2016
Rajendra Singh; Ashok Kumar; Arun Kumar Singh; John Coggan; Sahendra Ram
International Journal of Rock Mechanics and Mining Sciences | 2017
Sahendra Ram; Dheeraj Kumar; Arun Kr. Singh; Ashok Kumar; Rajendra Singh
Journal of The South African Institute of Mining and Metallurgy | 2004
Rajendra Singh; Sahendra Ram; Amit Kumar Singh; Shailly Prasad; J. Buragohain
International journal of mining science and technology | 2016
Rakesh Kumar; Arvind Kumar Mishra; Arun Kumar Singh; Amit Kumar Singh; Sahendra Ram; Rajendra Singh
Archive | 2009
Arun Kumar Singh; Rajendra Singh; Prabhat Kumar Mandal; Rakesh Kumar; Amit Kumar Singh; Sahendra Ram
Archive | 2004
Prabhat Kumar Mandal; Arun Kumar Singh; Sahendra Ram; Amit Kumar Singh; Rajendra Singh
Procedia Engineering | 2017
Rajendra Singh; Sahendra Ram; Arun Kumar Singh; Ashok Kumar; Rakesh Kumar; Amit Kumar Singh
Archive | 2016
Arun Kumar Singh; Sahendra Ram; Rajendra Singh; Ashok Kumar