Abstract：In coal mining，hard roof collapse control of steeply dipping coal seams is a challenging problem，and hence，investigations of the collapse mechanism and control method of the hard roof in steeply dipping coal seams are crucial to coal mine safety production. In this study，the mechanical properties of coal-rock strata were analyzed through field investigations and indoor tests，and the collapse mechanisms，characteristics and range of the hard roof in steeply dipping coal seams were exploited by indoor similar material simulation experiments and discrete element numerical calculations. A presplitting blasting scheme of the hard roof was designed，and the collapse control scheme of the hard roof was simulated using the discrete element method and compared with the actual application. The results show that the rock stratum of the hard roof exhibits visible elastic-brittle-plastic failure characteristics and that the elastic-brittle-strain softening constitutive model used to evaluate the failure process of the coal-rock contact surface can reasonably reflect the failure characteristics of the steeply dipping coal seam roof. The results of both 3DEC simulations and similar material simulation experiments reveal that the steeply dipping hard roof deforms inconspicuously along the trend and is not easy to collapse along the strike under the short-wall mining condition，and that it is easy to form a large-area suspended roof with a span of 75–85 m in the rear goaf accompanied by obvious sudden collapse. A numerical calculation approach for calculating the advanced deep hole presplitting blasting roof was proposed based on the discrete element method，and the comparison between the simulation results with the actual application results validates the feasibility of applying this method to hard roof control.
孙 闯，陈东旭，程耀辉，卢嘉鑫. 急倾斜煤层坚硬顶板塌落规律及控制研究[J]. 岩石力学与工程学报, 2019, 38(8): 1647-1658.
SUN Chuang，CHEN Dongxu，CHENG Yaohui，LU Jiaxin. Study on collapse rule and control of hard roofs in steeply inclined coal seams#br#. , 2019, 38(8): 1647-1658.
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2019, Vol. 38 
