Research on the response characteristics of explosion stress-strain fields of rock-like materials under different blast loading intensities based on DIC

Abstract The dynamic response of medium during blasting fragmentation is critically governed by the explosive charge weight. To elucidate the evolution and attenuation of the blast-induced stress–strain field under varying charges, this study employed two-dimensional model experiments integrated with ultra-high-speed Digital Image Correlation (DIC) technique. Experimental results revealed a three-stage evolution process for both transverse and longitudinal strain fields: (1) formation and expansion of the initial compressive strain zone; (2) emergence of the tensile strain zone; and (3) interaction of different strain zones culminating in a closed annular strain zone. Both radial and circumferential stresses exhibited exponential attenuation with distance, notably with a significantly higher attenuation exponent for circumferential stress compared to radial stress. Crucially, the stress field demonstrated heightened sensitivity to charge weight variations near the blast hole center, while this influence diminished rapidly in regions farther away. Furthermore, analysis identified a critical radial distance zone: circumferential stress dominated within this zone, while radial stress prevailed beyond it.