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A high-energy gas rock-breaking material and method suitable for shallow hole blasting has been proposed. The rock-breaking principle and law of high-energy gas were analyzed through laboratory rock-breaking experiments combined with CT scanning and three-dimensional reconstruction technology. The results showed that the specimen after the action of high-energy gas was broken evenly and the energy utilization rate was high. However, with the increase in the dosage, energy would be wasted and the rock would be over-crushed. According to the analysis of the deflagration pressure curve of high-energy powder, the action process of high-energy gas could be roughly divided into four stages: crack initiation, high-speed expansion, low-speed expansion, and pressure reduction. At the same time, the multi-level interaction mechanism of "gas expansion + detonation impact" between high-energy gas and rock mass was proposed. Finally, the superior rock-breaking effect of high-energy gas was verified through engineering application, which provides scientific guidance for the later scheme optimization. Highlights: Propose a high-energy gas rock breaking method applied in the field of shallow hole blasting, which is based on an energetic material. CT scanning technology can accurately describe the internal damage of rock mass. Revealed the multi-level interaction of "gas expansion + detonation impact" between high-energy gases and rock masses. [ABSTRACT FROM AUTHOR]

Aiming at the shortcomings of the current rock-breaking technology, a new type of high-energy expansion agent for energetic materials based on combustion-to-detonation was developed. By characterizing the basic physical and chemical properties of the high-energy expansion agent (HEEA) such as morphology, particle size distribution, and pyrolysis characteristics, the work performance of different types of high-energy expansion agents was analyzed in combination with the energy characteristics. The results showed that the relationship between the expansion work done by the gas to the outside world was WHEEA-I > WHEEA-II > WHEEA-III under the same quality of HEEA combustion. The damage effect of high-temperature and high-pressure gas cracking specimens generated by deflagration of HEEA was obvious, having the rule that the disturbance damage of rock caused by low heat and high gas specific volume was smaller, and the damage degree of rock caused by high heat and low gas specific volume was larger. The mechanism of HEEA combustion and detonation in confined space is revealed, which provides a theoretical basis for the application of HEEA-cracked rock. [ABSTRACT FROM AUTHOR]