节理倾角与孔间参数对层状岩体爆破裂纹扩展的影响

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中图分类号：O382；TD235 国标学科代码：13035 文献标志码：A

Abstract：Intheconstruction processofdrillngandblastingmethodforlayeredrock tunnel，theunbalanced distributionof explosioenergywaseasytocauseserious over-andunder-excavation.Thejointdipangle，inter-holedelay，andholespacing were the mai influencing parameters.The simulated rock massamples with diferent joint dip angles were prepared by the layered pouring method，andthe blasting test of layered rock mass was cariedout.Based on the ABAQUS simulation software，the blastingcrack propagationandstress wave propagationcharacteristicsoflayeredrockmassunder diferentjoint dipangles were analyzed.Theresults show that the joint dip angle has a significant guiding efect on the stress wave propagation.Byaffecting thestressdistribution，thepeak strainanddamagedegreeatdiferentpositionsare diferent，whichin tum promotesthe crack propagationatthe joint surfaceoraround the blasthole.The inter-holedelay playsakeyrole in regulatingthecrack propagation path.Withthe increaseofdelay time，thestresswavesuperpositionareaofthe pre-blasting hole and the post-blasting hole graduallyshifts fromthejoint center tothe surounding of the post-blasting hole，resulting in the peak strain and damage value ofthe joint center increasing first andthen decreasing，and the failure area of therock mass shiftstothepost-blasting holeaccordingly.However，toolongdelayweakens thesynergisticefectofthedouble-holestre wave.The increase ofhole spacing weakens thestresssuperposition inthecenterofthe joint，sothattheenergy is concentrated aroundtheborehole，andthecrack propagation modechanges fromjointpenetration toradial distributionaroundtheborehole. However， too largea hole spacing is easy to lead to the failure of crack penetrationbetwen holes due to insuficient energy attnuation and stressuperposition， which significantlyreduces thecrushing eficiencyofrock massThe research results are helpful to the understanding of blasting crack propagation in layered rock mass.

Keywords：layered rock mass; inter-hole delay;hole spacing; joint dipangle;stress wave

钻爆法因其具有经济高效的优点，被广泛应用于隧道及地下工程开挖等领域。（剩余16783字）