Kumar, Ashok and Singh, Arun Kumar and Kumar, Dheeraj and Ram, Sahendra and Kumar, Rakesh and Singh, Amit Kumar and Singh, Rajendra (2019) Caveability Assessment of a Hanging Overlying Massive Deccan Trap and its Effect on Underground. Insights in Mining Science and Technology, 1 (3). pp. 1-11.

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Abstract

Efficient and safe extraction of coal from underground mines require regular/smooth caving of the hanging overlying strata in goaf which is intended to fall. Sometimes presence of extremely difficult to cave massive strata (EDTCMS) having higher strength and thickness as immediate roof delays the natural caving and affect adversely the depillaring operation in underground mines. Such EDTCMS are found globally (India, China, United States, Czech Republic) with thickness varying to hundreds of meters characterised as igneous/sedimentary formations. It is found to be lying either just immediately above or after a certain parting from the coal seam. The latter is found more frequent to the former in coalfields of the world including India. Bulking factor plays a major role in filling the void by the falling of the partition between coal seam and EDTCMS. When a large overhang of EDTCMS is created in the void then their sudden breakage may generate issues like dynamic weighting, floor heaving, pillar spalling, coal bump/rock burst, goaf encroachment/pillar failure and air blast in and around the face. Dynamic weighting by a dolerite sill in the roof destroyed the integrity of almost half of the chock shields in less than 4 second at Churcha West Colliery, India. Various techniques have been adopted worldwide to deal with the issues due to EDTCMS like their pre-fracturing, induced blasting, leaving wider barrier pillars at the face, back filling and injection of grouting material into the mining-induced overburden. This paper presents a case study discussing issues of spontaneous heating and pre-mature collapse of pillars due to EDTCMS at Mathani Underground Mine.

Item Type:	Article
Uncontrolled Keywords:	EDTCMS; Depillaring; Immediate Roof; Caving; Dynamic Weighting
Subjects:	Thick Seam Mining
Divisions:	UNSPECIFIED
Depositing User:	Mr. B. R. Panduranga
Date Deposited:	06 Nov 2019 04:38
Last Modified:	06 Nov 2019 04:38
URI:	http://cimfr.csircentral.net/id/eprint/2051

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