Research on Rock Damage Evolution Based on Fractal Theory-Improved Dynamic Tensile-Compression Damage Model

According to the characteristics that dynamic tension of rock material is elastic brittle and compression plastic, based on previous studies, influence initial damage considered in established model, calculation formula threshold used evaluate whether surrounding affected by blasting given. classic impact model statistical mechanics theory, a compressive tensile constitutive under load proposed. Based proposed numerical simulation was carried out, results were compared with field measurement results. further clarify evolution load, fractal dimension theory introduced analyze loads different hole network parameters. The show axial direction blast hole, diameter main fracture extension. Tensile mainly occurs along direction, below bottom. Compared classical range obtained according especially depth bottom not much from measured value closest value. crack density 1 us, 90 aperture, 130 aperture larger than other working conditions. Among them, largest, followed aperture. At 2~3 us after initiation, cracks between two holes, radial circumferential around obvious formed blastholes; at 4~5 shock wave front decreased rapidly propagated outward form wave. propagation velocity smaller 1~3 initiation. In summary, reasonable has certain engineering practicability.