Research on the Response Characteristics of Explosion Stress-Strain Fields of Rock-like Materials under Different Blast loading Intensities Based on DIC

The weight of the explosive charge evidently influences the dynamic response characteristics of the medium during the rock fragmentation process through blasting. This study investigates the evolution process and attenuation law of stress-strain field subjected to varying explosive charge weights, using an experimental system equipped with ultra-high speed digital image correlation technique along with two-dimensional model experiments. The experimental results show that the evolution process of transverse and longitudinal strain field in the medium induced by blasting loads can be categorized into three stages: the formation and expansion of the initial compressive strain zone; the formation of tensile strain zone; and the interaction of different strain zones and formation of closed annular strain zone. The variation of both the radial stress and circumferential stress follow an exponential attenuation law, with the attenuation index of circumferential stress significantly exceeding that of radial stress. The stress field is found to be more sensitive to the variations in explosive weight in the near proximity of the center of the blast hole, while the stress field is relatively weakened in the regions away from the blast hole. While the circumferential stress dominates within the critical zone, the radial stress is more dominant outside the critical zone.