DIC Measurement on Stress Wave Propagation and Strain Field Distribution Induced by Deep Rock Blasting

Abstract

Abstract An ultra-high-speed digital image correlation system was applied in a blasting experiment that simulates the blasting response of deep rock under high ground stress. The full field strain evolutionary process of the specimen and the strain time histories of certain gauges were analyzed. Under a static stress field (simulating high ground stress), stress concentration occurs within three times the radius of the blasthole, and then, according to the region of stress concentration, the specimen plane was divided into near zone and far zone of the blasthole. There was no significant difference between deep and superficial formation in the law of explosive stress wave propagation in the blasthole far zone, which was based on the blasting compression zone, crack zone, and vibration zone, and elastic mechanics theory. Through nonlinear fitting, the explosive stress wave attenuation function between the maximum principal strain and the distance from the blasthole was obtained quantitatively, namely, by εmax=697+718·e−0.166·s. In addition, the strain value of the blasthole far zone caused by the combined action of the blasting stress field and the static stress field was equal to the linear superposition of the strain values caused by these two fields separately.