Study on effect of gangue thickness on stability of coal wall of working face gangue-bearing coal seam

doi:10.16265/j.cnki.issn1003-3033.2023.10.1713

Abstract

Abstract:

In order to recognize the influence of gangue thickness on the stability of the coal wall of gangue-bearing coal seam, theoretical analyses were used to derive a mechanical model for the shear damage of the entrapped gangue layer, numerical modeling of coal wall stability in gangue-bearing coal beds was developed, spatial distribution characteristics of horizontal displacement and vertical stress in front of coal wall under different thickness of gangue were analyzed. The results show that the front of the coal wall produced instability impact area is mainly located around the gangue layer, with the formation of the gangue layer as the center of the protruding area. When gangue thickness is small, the gangue layer presents a multi-block body joint damage, and when gangue thickness is larger, the gangue layer appears to be a single block body broken one by one. Mechanical analysis shows that the risk factor of damage to the gangue layer gradually decreases with the increase of gangue thickness, and the numerical simulation results are consistent with the theoretical analysis.

Key words: gangue-bearing coal seam, coal wall stability, gangue thickness, risk factor, shear failure

LI Guosheng, LI Zhenhua, DU Feng, WANG Wenqiang, XU Jie. Study on effect of gangue thickness on stability of coal wall of working face gangue-bearing coal seam[J]. China Safety Science Journal, 2023, 33(10): 183-191.

Figures/Tables 10

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岩性	厚度/ m	密度/ (g·cm^-3)	抗拉强度/MPa	黏聚力/ MPa	内摩擦角/(°)
粗粒砂岩	17.63	2 342.37	1.33	14.19	33
中粒砂岩	1.39	2 233.19	3.56	5.25	37
粉砂岩	1.15	2 343.27	3.92	13.98	30
粗粒砂岩	2.91	2 377.43	1.45	8.65	28
砂质泥岩	10.92	2 321.29	4.32	18.89	30
粉砂岩	37.09	2 324.93	4.89	22.43	27
砂质泥岩	4.31	2 403.26	6.66	27.79	26
夹矸	—	1 150.16	0.97	1.16	25
煤	6.56	1 274.31	1.38	2.51	30
粗粒砂岩	1.98	2 231.86	2.04	8.65	28
细粒砂岩	1.99	2 301.25	5.61	30.91	20