露天矿地下采空区爆破崩落法治理效果的数值模拟研究

发布时间：2018-11-11 09:46

【摘要】：爆破崩落法是治理露天矿地下采空区的主要手段,数值模拟是研究爆破崩落效果的有效工具。基于连续-非连续数值模拟方法(CDEM),利用朗道点火爆炸模型实现了炸药起爆过程的描述,利用考虑应变软化效应的Mohr-Coulomb模型及最大拉应力模型实现了围岩损伤破裂过程的模拟。以弓长岭铁矿何家采场采空区为研究对象,重点探讨了炮孔间排距、起爆延时等对该采空区上覆岩层损伤破裂程度、空区填充程度及空区内大块率的影响规律。计算结果表明:炮孔间排距对爆破效果的影响较大,随着间排距的增大,塌落至空区的大块率逐渐增大,且塌落范围逐渐减小。当间排距为17 m时,仅空区顶板附近出现局部塌落,地表岩层依然处于稳定状态。起爆延时对爆破效果的影响较小,当起爆延时大于42 ms以后,塌落至空区的岩体块度分布基本一致,仅大块率有所区别。为了确保爆破崩落法的治理效果,建议炮孔的间排距不大于7m,炮孔排间延时不小于42 ms。
[Abstract]:Blasting caving method is the main method to control underground goaf in open pit, and numerical simulation is an effective tool to study the effect of blasting caving. Based on the continuous-discontinuous numerical simulation method (CDEM), the detonation process of explosive is described by Landau ignited explosion model. The Mohr-Coulomb model and the maximum tensile stress model considering strain softening effect are used to simulate the damage and fracture process of surrounding rock. In this paper, the goaf of Ho family stope of Gongchangling Iron Mine is taken as the research object, and the effects of hole spacing and initiation delay on the damage and fracture degree of overlying strata, the filling degree of goaf and the mass ratio of hollow zone in this goaf are discussed. The results show that the blasting effect is greatly affected by the interval between the holes. With the increase of the distance between the holes, the ratio of the large pieces collapsing to the empty area increases gradually, and the collapse range decreases gradually. When the spacing is 17 m, only local collapse occurs near the roof of the hollow area, and the surface rock is still in a stable state. The initiation delay has little effect on the blasting effect. When the initiation delay is more than 42 ms, the rock mass fragmentation distribution is basically the same when the initiation delay is more than 42 ms, only the bulk rate is different. In order to ensure the control effect of blasting caving method, it is suggested that the interval between the holes should not be more than 7 m, and the delay between the holes should not be less than 42 ms..
【作者单位】：鞍钢矿业爆破有限公司;中国科学院力学研究所;中国科学院流固耦合系统力学重点实验室;
【基金】：国家重点研发计划项目(2016YFC0801600)资助鞍钢矿业集团“基于采选总成本的爆破技术优化研究”项目(2016-科A07-2)资助
【分类号】：TD854.2

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