TY - JOUR
TI - Direct tensile mechanical properties and acoustice mission characteristics of coal at different depths of Pingdingshan mining area
AU - Zhang Zhi-Long
AU - Zhang Zhao-Peng
AU - Wang Man
AU - Zhang Ru
AU - Gao Ming-Zhong
AU - Zhang Ze-Tian
AU - Xie Jing
JN - Thermal Science
PY - 2021
VL - 25
IS - 6
SP - 4495
EP - 4503
PT - Article
AB - Uncertainties in the basic theory of shallow mining that continues to be used  in deep mining result in frequent engineering disasters with deep  characteristics. Thus, it is necessary to elucidate the mechanism of  mechanical deformation and failure behavior of coal from shallow to deep  depths. Coal samples from the same coal seam in the Pingdingshan mining area  of Henan Province were obtained at depths of 300 m, 600 m, 700 m, 850 m, and  1050 m. Direct tensile tests were conducted on the coal samples obtained at  different depths. The tensile strength exhibits as low decreasing trend with  increasing depth, reaching a minimum at 1050 m. This variation trend is  consistent with that of acoustic emission cumulative ring-down counts and  the cumulative energy measured during tensile tests on coal samples obtained  at different depths. These conclusions provide a reference for the  differences between the mechanical behavior of shallow and deep coal, which  has both theoretical and engineering significance.