静态爆破剂水化速率对矿体力学及损伤作用机制研究

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

为了研究静态爆破剂水化速率对矿体力学及损伤作用机制,利用应力-损伤耦合模型进行了不同水化速率下矿体力学损伤数值模拟,分析了水化速率对矿体应力场及损伤区演化规律影响,揭示了钻孔布置模型对水化速率作用的机制。研究结果表明:静态爆破损伤区发育可以分为压实阶段、微损伤形成阶段、损伤区发育阶段、损伤区贯通阶段等4个阶段,其中损伤区发育、贯通阶段应力作用最为显著;矿体应力场及损伤区随着水化速率的增大而增加,并且在快速释能初期水化速率对应力场及损伤区影响差异性较小,快速释能后期水化速率对应力场及损伤区影响差异性显著;钻孔布置模型影响水化速率作用机制,其中单孔力学模型下水化速率促进膨胀压差异性,双孔力学模型下水化速率促进应力叠加,导向孔布置模型最为显著,初期水化速率加快应力运移,后期水化速率促进应力叠加,在时间维度和应力维度的共同作用下造成损伤区扩展、贯通;本次数值模拟和现场测试方案中,静态爆破剂水化速率1.8 MPa/min,钻孔直径113 mm,钻孔间距1000 mm,合理的孔间距与钻孔直径比η=9,导向孔布置模型可有效地致裂矿体、产生大量损伤区。该研究为提高静态爆破技术的致裂效果及施工布置提供了参考依据。

For the purpose of studyingTo study the influence of hydration rate of static explosives on the mechan-ical 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 drlling ar-rangement 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 con-nection stages show the most significant stress effects.The stress field and damage zone increaseincreases with the in-crease 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 dfferent 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 mechani-cal model.The guided hole arrangement model has the most significant effect,where the initial hydration rate acceler-ates stress transfer and the later hydration rate promotes stress superimposition,leading to the expansion and connec-tion 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 di-ameter 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 ofma-ny damage zones.This research provides a reference basis for improving the fracturing effect and construction ar-rangement of static blasting technology.