With the open-pit mine slope of Sijiaying Yanshan Iron Mine as an example, biotite granulite specimens from the deep parts of the eastern and northern slopes of the stope were selected for impact tests, freeze-thaw cycle tests and mechanical loading tests, and the fracture characteristics of biotite granulite with different damage degrees under the combined action of freeze-thaw cycles and loading were studied. The results show that under freeze-thaw action, both the mass loss rate and porosity of biotite granulite present approximately linear increase as degree of damage increases. For biotite granulite with different initial damage degrees, the uniaxial compressive strength and elastic modulus all decrease after freeze-thaw cycles. It is shown that intact biotite granulite under loading and freeze-thaw cycles is dominated by splitting failure, while biotite granulite with initial damage is dominated by shear failure and combined tensile shear failure.
| 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 |