围压作用下等离子体的爆破破岩效应

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中图分类号：0383 国标学科代码：13035 文献标志码：A

Abstract：Plasma blastingrock breakingtechnologyisharacterzedbygren，higheficiencyontrollabilityandhaagood application prospect in deeprock breaking.Inorder to provide anewrock-breaking method fortherock-breaking enginering under deep stress，four groups of plasmasandstone blasting testsunder different peripheral pressures werecarriedout.The morphology，structure and distribution of thre-dimensional cracks inside therock were comparativelyanalyzed by CT scaningandthre-dimensionalreconstruction，soastostudytheefectivenessoftheplasma blastingtechnologyinrock breaking under diferent peripheral pressures. Meanwhile numerical simulation was conducted byusing LS-DYNA to establish theplasma equivalentexplosivemodel，supplementingtheverificationoftheroleofplasmablastinginthecoupledstresfield， and investigating the mechanism of plasma blasting underdiffrent pressures，as well as the internal crack expansion， distributionand damage evolution laws intherock body inthe blasting process.Theresults showthatunder thesame voltage， withthe increaseofthe 3Dperipheral pressre，thenumberanddistributionrange ofcracksonthesurfaceoftherock exhibit a trendof gradual reduction，whilethe complexityof the cracks within the sandstone and thedepthof penetration are significantlyreduced.Due to the dynamic stressfield generated by plasma blastingand the staticstresscoupling field generated bythe surounding pressure，the shock wave generated bythe plasma blasting intheinitial stage of the explosion plays amajorrole forthe effectof diferent pressures under the action of therock crack morphology and thecenter of the expansion of the region does not show obvious diferences.With the attenuation of the shock wave，the 3D surrounding pressure inthe middleandlate stages ofthe plasma blasting processplaysa decisiverole in inhibiting the cracksoftherock massexpansionanddamage evolution.At thesame time，withthe increaseofthesurounding pressure，themore significant inhibition effect on the expansion ofcracks intherockbody，resulting inthe body fractal dimension and damage degree of 3D cracks intherockbody，whiletheroleof thesurrounding pressure approximately follows alinarlydecreasingrelationship.

Keywords：plasma explosion; confiningpressre; crack spatial morphology; three-dimensional reconstruction; LS-DYNA

随着浅层矿物资源的不断开采直至枯竭，深部矿物资源的开采逐渐成为一种趋势[]。（剩余21100字）