Title: Mechanisms of the abnormal first weighting in 'knife handle shaped face' with 7.0 m high supports

Authors: Jinfeng Ju; Jialin Xu; Zhenjun Shan

Addresses: Internet of Things/Perception Mine Research Centre, China University of Mining and Technology, Xuzhou, Jiangsu, 221008, China; The National and Local Joint Engineering Laboratory of Internet Application Technology on Mine, Xuzhou, Jiangsu, 221008, China ' State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology, Xuzhou, Jiangsu, 221116, China ' School of Civil, Mining and Environmental Engineering, University of Wollongong, Wollongong, New South Wales, 2500, Australia

Abstract: During the mining process of the 'knife handle shaped face' (KHSF) No. 52304-1 with 7.0 m high supports in Daliuta coal mine, the first weighting intensity was extraordinarily weak although the mining distance reached 171 m. This was quite different from the current experience. In this research work, field measurements and theoretical analysis were conducted to study the mechanisms of this uncommon phenomenon. The results showed that, the sub key stratum 1 (SKS 1), which commonly played a major role in mining face strata behaviour, had broken before the first weighting. And because of its high horizontal distance above the coal seam, its long breakage interval, as well as the large bulking factor of the immediate roof, its breakage did not have influence on the mining face. Therefore, the reason for the unusual weighting intensity of first weighting was not because of the breakage of SKS 1 but due to the fracturing of the upper primary key strata (PKS). Also, as PKS was far away from the coal seam, its breakage had only little influence on mining face so that the weighting intensity was quite weak. [Received: April 19, 2013; Accepted: November 7, 2013]

Keywords: coal technology; 7.0m high supports; knife handle shaped face; KHSF; first weighting; abnormal weighting intensity; key stratum; mining industry; mine supports; coal mines; strata fracture.

DOI: 10.1504/IJOGCT.2015.069002

International Journal of Oil, Gas and Coal Technology, 2015 Vol.9 No.3, pp.348 - 358

Received: 23 Apr 2013
Accepted: 01 Nov 2013

Published online: 24 Apr 2015 *

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