The presence of near-field fracture clusters plays a critical role in governing the mechanical behavior of fracture initiation during hydraulic fracturing processes. This study systematically investigates the mechanical properties and fracture propagation mechanisms in granite through uniaxial hydraulic fracturing tests, acoustic emission monitoring, and digital image scanning techniques. Statistical analysis of the experimental data shows that near-field fracture clusters induce significant reductions in fracture initiation pressure, acoustic emission activity, and energy dissipation, all of which follow an exponential decay pattern. When fracture density exceeds two cracks, the attenuation rate of the cracking pressure has decreased significantly, indicating a diminishing influence of fracture quantity on pressure reduction. Fracture surface morphology exhibits statistically significant variations under different fracture cluster configurations, with fractal dimension demonstrating a positive correlation with fracture density. The increasing complexity of fracture surfaces with higher fracture density is characterized by a negative linear relationship between fractal dimension and initiation pressure.
| 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 |