In order to reveal the influences of super-thick and hard strata on abutment pressure and the evolution law of energy distribution in stope, a typical mining area of Yangliu Coal Mine was taken as the research object, and the variation law of abutment pressure and energy evolution process were simulated by numerical simulation method. The results are concluded as follows. (1) When there are super-thick and hard strata in the overlying strata, the advance abutment pressure in the middle and both sides of the working face is increased by about 9% and 5% respectively compared with that without super-thick and hard strata. This shows that when there are super-thick and hard strata in the overlying strata, the middle and both sides of the stope are in a high stress state for a long time. When the stope is disturbed by external force, it is more likely to lead to the occurrence of dynamic disasters such as mine earthquake and rock burst. (2) When there are super-thick and hard strata in the overlying strata, the change curve of the advance abutment pressure of the stope shows a cliff-like decline after breaking. When there are no super-thick and hard strata in the overlying strata, the change curve of the advance abutment pressure of the stope is gentler than that of the former. (3) With the continuous advancement of the working face distance, the peak value of the abutment pressure of the free side is increased by 3.60 MPa and 3.39 MPa respectively compared with the peak value of the abutment pressure of the mining side when there are or are not super-thick and hard strata in the overlying strata. The change trend of the side abutment pressure of the two is basically the same, but the side abutment pressure of the free side of the roadway is obviously larger than the lateral abutment pressure of the mining side of the roadway. This shows that the existence of super-thick and hard strata makes the stress concentration, roadway mining will be more prone to damage. (4) The super-thick and hard strata will cause great impact on the stope after breaking. Compared with the stope without super-thick and hard strata, the damage degree is more severe, the elastic energy released is more, and the influence range is more extensive.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |