Title: Investigation of coal burst characteristics under impact loading
Authors: Guangjian Liu; Zonglong Mu; Junliu Du
Addresses: State Key Laboratory of Coal Resource and Safe Mining, Laboratory of Mine Earthquake Monitoring and Prevention; School of Mines, China University of Mining and Technology, Xuzhou, Jiangsu 221116, China ' State Key Laboratory of Coal Resource and Safe Mining, Laboratory of Mine Earthquake Monitoring and Prevention; School of Mines, China University of Mining and Technology, Xuzhou, Jiangsu 221116, China ' State Key Laboratory of Coal Resource and Safe Mining, Laboratory of Mine Earthquake Monitoring and Prevention; School of Mines, China University of Mining and Technology, Xuzhou, Jiangsu 221116, China
Abstract: Under condition of static loading, although the coal seams in some collieries were of weak burst proneness, still there were occurrences of coal bursts. This paper investigates the coal burst proneness under varying impact loading rates, peak impact loads and loading cycles in terms of four indices, i.e., Rc, DT, WET and KE. An acoustic emission (AE) system recorded the coal sample failure and consequently the development of fractures in coal samples was analysed through AE count under different loading conditions. The above mentioned four indices could be directly obtained from the stress vs. strain relationship and are normally used to assess coal burst proneness. The coal burst is a natural process of crack development and energy conversion. The laboratory test results depicted strengthening of coal samples' burst proneness with the increase in loading rate and peak impact load and weakening with the increase in loading cycles. [Received: February 4, 2017; Accepted: November 7, 2017]
Keywords: coal burst proneness; impact loading; AE count; laboratory test; energy conversion; discrete element method; theoretical calculation; uniaxial compressive strength; dynamic failure time; elastic energy index; burst energy index; coal technology.
DOI: 10.1504/IJOGCT.2018.091552
International Journal of Oil, Gas and Coal Technology, 2018 Vol.18 No.1/2, pp.118 - 145
Received: 04 Feb 2017
Accepted: 07 Nov 2017
Published online: 04 May 2018 *