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聚能效应在岩土工程爆破中的应用研究
Application Study on Blasting in Rock with Shaped Charge
【作者】 罗勇;
【导师】 沈兆武;
【作者基本信息】 中国科学技术大学 , 工程力学, 2006, 博士
【摘要】 本文对聚能药包应用于岩石定向断裂爆破进行了研究。随着科学技术的发展,越来越多地牵涉到聚能装药对岩土的侵彻问题。为了获得平整的岩石开挖面和井巷轮廓线,提高石料开采的成材率,同时,为了降低巷道围岩受损伤的程度,以便提高其稳定性能,普通的光面爆破已经不能适应生产的需求,而在其基础上发展起来的岩石定向断裂爆破得到了广泛的应用,聚能药包岩石定向断裂爆破就是一种用药量少,效果好的方法。线型聚能装药切割岩石爆破的过程是一个十分复杂的二维非定常流动力学过程,而且岩石的性质相当复杂,各种裂隙、节理发育,给理论计算和现场实验带来许多困难。 本文首先对聚能射流的侵彻机理进行了分析,总结了前人研究的聚能射流侵彻的工程计算,并给出了定常理想不可压缩、准定常理想不可压缩、考虑靶体强度的准定常不可压缩的聚能射流对靶体侵彻深度的表达式,以及聚能射流的径向侵彻计算公式和聚能射流形成的临界条件,即药型罩的压垮速度必须小于材料的体积声速,否则射流将是非凝聚的和扩散的。 同时,本文总结了爆破理论的形成及发展,对爆炸应力波在岩体中的传播特性进行了分析。基于爆炸动力学、岩石断裂力学理论,从宏观上对聚能药包用于岩石定向断裂爆破时导向切裂缝的形成,切缝尖端裂纹的形成、起裂、扩展和贯通进行了研究,以及对装药结构、用药量和炮孔间距的设计进行了理论阐述,给出了主要爆破参数计算公式;同时从分子微观结构的作用势来对聚能效应做了一些探讨与分析。将炮孔周围岩体看成具有圆形孔道的无限大弹性体,称粉碎区以外的裂隙扩展范围为塑性区,裂缝(隙)区以外为弹性区。应用爆破冲击波理论,推导了炮孔周围的粉碎区、裂缝(隙)区内的应力大小及各区的范围,从理论上建立了炮孔装药量与致裂范围即炮孔间距之间的关系。从理论上对炮孔堵塞物的作用机理及其在炮孔中运动规律的进行了探讨,推导出了炮孔
【Abstract】 With the development of science and technology, more and more rock blasting relate to shaped charges. In order to get excavated faces with even faces in rock blasting, to increase the finishing product rate in mining rock, and to improve the stability of surface profiles, the ordinary smooth blasting can’ t satisfy all requirements from all sides. The directional fracture controlled blasting, which is an emerging blasting methodology that is developing in recent years by utilizing the advantages of smooth blasting, is widely used in rock blasting. The directional fracture controlled blasting with shaped charge is a satisfied blasting with a little explosive. The process of cutting rock with LSC (linear shaped charge) is a complex one of two-dimensional non-steady dynamics, and the complexity of rock mass feature brings many difficulties to related theoretical researches and field experiments.Penetration mechanism of cumulative energy jet is analyzed and engineering calculation of jet is generalized, the calculation expressions related to penetration and critical condition of forming cumulative energy jet are summarized. At the same time, formation and development of blasting theories, the propagation characteristic of explosion stress wave in rock are expounded.Based on the dynamics of explosion and fracture mechanics, the mechanism of crack initiation and its expansion of directional fracture controlled blasting by shaped charge with wedge-type liners in rock were rough studied macroscopically. The blasting parameters and their designs are expounded, and cumulative energy effect is in detail discussed by molecular interaction potential in a microscopic level. In paper, the rock around boreholes are considered infinite elastic mass with circular drill way,
【Key words】 dynamics of explosion; fracture mechanics; shaped charge; liner; directional fracture controlled blasting; penetration; numerical simulation;