(1. 华南理工大学 土木与交通学院,广州 510640;
2. 华南理工大学 安全科学与工程研究所,广州 510640)
摘 要: 临界爆破振速是影响胶结充填体矿柱稳定的关键因素,目前理论研究相对薄弱。本文综合考虑覆岩和自重力、爆破扰动力和充填体侧压力对胶结充填体矿柱的耦合作用,构建了矿柱失稳临界爆破振速理论模型,给出了拉伸、压缩和综合破坏的临界振速vtmax、vcmax、vmax数学表达式,定量研究矿柱临界爆破振速与充填体的灰砂比、高度(h)及宽度(b)尺寸因素之间关系。结果表明:在外力耦合作用下,当矿柱几何尺寸保持一定时,临界爆破振速随着灰砂比增加而增大;当矿柱宽度一定时,临界振速随着高度增加而逐渐减小,破坏形式由拉伸破坏转为压缩破坏;当矿柱高度一定时,临界爆破振速随着宽度增加而增大,充填体的破坏形式为拉伸破坏。现场工程验证了理论模型的计算结果合理性。研究成果为矿山安全生产提供理论支撑。
关键字: 临界爆破振速;胶结充填体矿柱;力学模型;灰砂比;几何尺寸
(1. School of Civil Engineering and Transportation,South China University of Technology, Guangzhou 510640, China;
2. Institute of Safety Science and Engineering, South China University of Technology, Guangzhou 510640, China)
Abstract:The critical blasting vibration velocity is the key factor affecting the stability of the cemented backfill pillar. The current theoretical research is relatively weak. This paper comprehensively considers the coupling effect of overburden and self-gravity, blasting-disturbance and lateral pressure on cemented backfill pillars. And a theoretical model for the critical blasting vibration velocity of the pillar instability was constructed. Accordingly, the mathematical expression of critical velocities vtmax, vcmax and vmax for the tension, compression and comprehensive failure were established. Meanwhile, the relationship between the critical blasting vibration velocity of the pillar and the sand-cement ratio, height (h) and width (b) of the filling body were investigated. The results indicate that, under the external force coupling, when the pillar geometry maintains a certain value, the critical blasting vibration velocity increases with the increase of the cement sand ratio. When the width of the pillar is constant, the critical vibration velocity gradually decreases with the increase of the height, and the failure mode changes from tensile failure to compression failure. When the height of the pillar is constant, the critical blasting vibration velocity increases with the increase of the width, and the failure form of the filling body is tensile failure. The field engineering verified the rationality of the calculation results of the theoretical model. The research results provide theoretical support for mine safety production.
Key words: critical blasting vibration velocity; cemented backfill pillar; mechanical model; cement sand ratio; geometry