Mechanism of slabbed spalling failure of the coal face in fully mechanized caving face with super large cutting height

被引：0

作者：

Xu Y. ^{[1
,2
,3
]}

Wang G. ^{[1
,2
,3
]}

Li M. ^{[1
,2
]}

Xu Y. ^{[1
,2
,3
]}

Zhou C. ^{[4
]}

Zhang J. ^{[1
,2
,3
]}

机构：

[1] Coal Mining Research Institute, China Coal Technology and Engineering Group, Beijing

[2] Coal Mining Branch, China Coal Research Institute, Beijing

[3] State Key Laboratory of Coal Mining and Clean Utilization, Beijing

[4] Shenzhen Clean Energy Research Institute, Shenzhen

来源：

Caikuang yu Anquan Gongcheng Xuebao/Journal of Mining and Safety Engineering | 2021年 / 38卷 / 01期

关键词：

Extra-thick coal seam; Fully mechanized caving mining; Hard coal seam; Shallow cover depth; Slabbed spalling failure; Super large cutting height;

D O I：

10.13545/j.cnki.jmse.2019.0416

中图分类号：

学科分类号：

摘要：

In view of the technical conditions of shallow covered, extra-thick and hard coal seam in Yushen mining area, through site observation, rock mechanics test, and theoretical analysis, the failure mode and mechanism of coal face were investigated in extra-thick and hard coal seam with super large cutting height and fully mechanized coal caving operation. The site investigation has shown that the main failure mode of coal face is vertically slabbed buckling spalling. The failure modes of primary slabbed buckling spalling at the coal face could be classified as slab-like spalling, onionskin-like. spalling, ejection-type spalling, and spalling caused by disturbance of face sprag of hydraulic roof supportsrock mechanics tests have indicated that vertically splitting failure of test specimens are more prone to occur under conditions of low confining pressure and unloading confining pressure. The slabbed buckling spalling of coal face is a type of structurally dominant failure induced by unloading environment under the high mining stress at the longwall face. The failure modes of different types of slabbed buckling spalling are mainly related to the microstructure of coal mass and difference of stress environment. Combined with the stress environment of coal face, the mechanism of slabbed buckling spalling of coal face has been analyzed from both macro and micro perspectives. The mechanical mechanism of the development of slabbed buckling spallinghas been analyzed and explained with damage and fracture mechanics as well as plate mechanics. The plate structure is formed by the expansion and coalescence of discontinuous vertical cleats, and different types of failure of the plate structure occur under the corresponding stress environment. This research would enrich cases and theory of slabbed buckling, which could provide theoretical reference for the control and prevention of slabbed buckling spallingin fully mechanized caving face with super large cutting height. © 2021, Editorial Board of Journal of Mining & Safety Engineering. All right reserved.

引用

页码：19 / 30

页数：11

共 30 条

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