Characteristic Fracture Pattern and Fragment Size Distribution in Rocks due to Stress Waves in Blasting

用炸药破碎岩石是提取有价值矿物的首选方法。它也是大多数土木工程开挖作业的首选方法。然而，尽管这种做法非常普遍，但准确预测特定炸药-岩石组合的爆破结果仍然非常困难，因为它涉及大量变量，其对爆破结果的影响尚不能量化。碎片大小分布的预测及其控制将是所有采矿和采石作业的一项非常重要的改进。它们影响所有的“下游”操作，如装载、粉碎、研磨和碾磨。这些问题不仅直接关系到运营的经济性，而且还关系到运营的安全。目前还不可能预测大爆炸的所有方面，但逐步改善我们对炸药类型、爆炸设计和目标岩石相关特性之间的相互关系的了解，将大大有助于实现最终目标。然而，在过去的几十年里，几个研究小组在确定关键变量方面取得了相当大的进展，其中包括本文作者自己的研究小组。其中之一是钻孔中爆炸作用引起的破裂过程与爆炸中最终的破片尺寸分布之间的联系。然而，在大规模作业中对所有相互关联的参数进行系统调查是不可行的，因此需要对具有良好特性的岩石和炸药进行受控测试和高级分析。这项拟议的研究旨在开发一个这样的‘积木’，我们试图开发一个可预测的和可靠的片段预测模型。

Rock fragmentation by explosive is the preferred method of extraction of valuable minerals. It is also the preferred method for most civil excavation operations. However, despite overwhelming prevalence of the practice, accurate prediction of blast results for a given explosive-rock combination has remained exceedingly difficult, as it involves a very large number of variables whose effect on blast results is yet to be quantified. Prediction of fragment size distribution and its control would be a very significant improvement in all mining and quarrying operations. They affect all 'downstream' operations such as loading, crushing, grinding and milling. These have direct bearing not only on the economics of the operations but also on their safety. It is not possible at this time to predict all aspects of a large blast, but incremental improvement in our understanding of interrelationship between explosive type, blast design and relevant properties of the target rock would go a long way to meeting the ultimate objective. Considerable progress in our understanding of the blasting process has been made however during the last few decades by several research groups including this author's own in identifying the key variables. One of these is the link between fracture process due to explosive action in the borehole and the eventual fragment size distribution in a blast. However, systematic investigation of all the interconnecting parameters in large-scale operations is not feasible, hence the need for controlled tests and advanced analysis on well characterized rocks and explosives. This proposed research is aimed at developing one such 'building block' in our attempt to develop a predictive and reliable fragment prediction model.