Study on Mechanism of Hydration Rate of Static Blasting Agent on Rock Mechanics and Damage

For the purpose of studyingTo study the influence of hydration rate of static explosives on the mechanical behavior and damage mechanism of coal ore body, numerical simulations of ore body mechanical damage were carried out using a stress-damage coupling model under different hydration rates. The impact of hydration rate on the evolution of stress field and damage zone in the ore body was analyzed, and the mechanism of the effect of drilling arrangement model on hydration rate was revealed. The research results indicate that the development of the damage zone in static blasting can be divided into four stages: compaction stage, micro-damage formation stage, damage zone development stage, and damage zone connection stage. Among them, the stages of damage zone development and connection stages show the most significant stress effects. The stress field and damage zone increaseincreases with the increase in of hydration rate. Specifically, and the influence of hydration rate on the stress field and damage zonesuch kind of influence is relatively small during the initial rapid energy release phase, but becomes significantly different in the later stages. Besides, Tthe borehole arrangement model affects the mechanism of hydration rate.withUnder the single-hole mechanical model, the hydration rate promotes expansion pressure differences, while However, the under the double hole mechanical model, hydration rate promotes stress superimposition forunder the double hole mechanical model. The guided hole arrangement model has the most significant effect, where the initial hydration rate accelerates stress transfer and the later hydration rate promotes stress superimposition, leading to the expansion and connection of the damage zone under the combined effects of time and stress dimensions. In the numerical simulation and field tests scheme of this study, the hydration rate of the static blasting agent was 1.8 MPa/min, the blast orehole diameter was 113 mm, the borehole spacing was 1000 mm, and the reasonable ratio of borehole spacing to diameter(η) was 9. The guided hole arrangement model can effectively fractures the ore body and generatees a large number ofmany damage zones. This research provides a reference basis for improving the fracturing effect and construction arrangement of static blasting technology.