Aiming at the problem of non-homogeneity and difficulty in obtaining the mechanical parameters of surrounding rock in the process of coal mining, the experimental device for determining the parameters of loaded coal rock with drilling was developed independently to realize the real-time perception of strength and structure of rock layer. The effects of circumferential pressure, drilling speed, rotational speed and rotational torque on strength of simulated rock specimens were investigated and analyzed by coupling the gray correlation of collected parameters with drilling. Under loaded conditions, stratified specimens of different combinations of types were drilled in order to restore the actual effect of drilling into coal and rock seams in real environments, and to verify the accuracy of identification of compressive strength of specimens by the following drilling parameters. It was shown that the strength of the specimens was positively correlated with the circumferential pressure, rotating torque and drilling speed. The strength of the specimen remained almost constant when the rotational speed varied. The correlations between rotational torque, circumferential pressure, drilling speed, and rotational speed and compressive strength were 0.996, 0.831, 0.739, and 0.347, respectively. The strength of the specimen was linearly related to the rotational torque. By analyzing the features of change in the rotating torque curve, the strength of the rock formation can be identified and thus the location of the stratum boundary can be located.
| 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 |