Ground control strategies for burst prone mines

随着加拿大矿山继续开采更深的矿床，越来越重视地面控制措施，以处理由于高原地应力导致的各种形式的灾难性岩石破坏（如应变破裂、支柱破裂和断层滑动破裂）而导致的岩石不稳定问题。该研究计划的长期目标是促进实用工具的开发，帮助采矿作业采取适当的地面控制措施来缓解和控制岩爆。在短期内，该研究计划包括以下五个研究项目。第一个项目（MSC 1）研究了大规模的面板卸压爆破，这是当一个矿柱是高应力时使用。该项目旨在优化主要设计参数，即1）矿体接触面与盘区之间的间距，2）爆破盘区宽度和3）盘区延伸超出矿柱界限。方法是基于数值模拟和现场数据分析。项目2（博士1，UG 1至3）旨在调查加拿大矿山硬岩的内在特性。其目的是更好地了解岩石的内在性质，如粒度和矿物成分对岩石的爆裂行为的影响。这项工作涉及使用扫描电子显微镜，粉末X射线衍射，颗粒流代码模拟（PFC）和实验室测试。项目3（PhD 2，UG 4和5）将研究高应力环境下的钻孔变形和崩落。目标是制定一种方法来估计采矿引起的压力，以帮助就地面控制战略作出明智的决定。该项目将测试和开发两种不同的方法-一种是基于变形测量，另一种是基于强制突破。该方法包括CAD设计和制造，数值建模，实验室和现场测试。在项目4（MSC 2）的实验室和项目5（MSC 3）的现场，对在载荷下钻孔开槽以减少周围应力的概念进行了探讨。目的是找出钻孔开槽是否可以成为一种实用的手段，通过钻孔的自破裂的局部能量耗散。这项工作包括实验室和现场测试以及数值模拟。作为一个全球矿产生产国，加拿大需要在岩石工程、地下采矿和岩爆控制方法方面具有知识和技能的HQP。该研究计划为10名HQP即2名博士，3名MSC和5名本科生（UG）的培训提供了独特的机会。拟议的钻孔变形和崩落工作（项目3）的应用范围远大于本提案中所述的应用范围。它在土木工程隧道和钻井稳定性工程中具有潜在的应用。因此，技术突破可以找到更广泛的最终用户。

As Canadian mines continue to reach deeper deposits, more emphasis is being placed on ground control measures to deal with rock instability issues due to high in-situ stress leading to various forms of catastrophic rock failures such as strain burst, pillar burst, and fault-slip burst. The long-term objective of this research program is to contribute to the development of practical tools that would help mining operations take appropriate ground control measures to mitigate and control rockbursts. In the short term, this research program encompasses five research projects as follows. The first project (MSC 1) examines large-scale panel destress blasting, which is used when an ore pillar is highly stressed. The project aims to optimize the main design parameters namely 1) stand-off distance between the orebody contact and the panel, 2) blasted panel width and 3) panel extension beyond the ore pillar limits. Methodology is based on numerical modelling and analysis of field data. Project 2 (PhD 1, UG 1 to 3) seeks to investigate a range of Canadian mine hard rocks for their intrinsic properties. The goal is to better understand the influence of intrinsic rock properties such as grain size and mineral composition on the bursting behaviour of the rock. The work involves the use of scanning electron microscope, powder X-ray diffraction, particle flow code simulation (PFC) and laboratory testing. Project 3 (PhD 2, UG 4 and 5) will investigate borehole deformation and breakout in high stress environment. The goal is to develop a methodology to estimate mining-induced stress to help make informed decisions on ground control strategies. The project will test and develop two different approaches - one that is based on deformation measurement, and another based on forced breakout. The methodology involves CAD design and fabrication, numerical modelling, laboratory and field testing. The notion of notching boreholes under load to reduce the surrounding stress is explored in laboratory in Project 4 (MSC 2) and in the field in Project 5 (MSC 3). The aim is to find out if borehole notching could become a practical means for local energy dissipation through self fracturing of the boreholes. The work encompasses laboratory and field testing and numerical modelling. As a global mineral producer, Canada needs HQP with knowledge and skills in rock engineering, underground mining and rockburst control methods. This research program offers a unique opportunity for the training of 10 HQP namely 2 PhD, 3 MSC and 5 undergraduate (UG) students. The proposed work on borehole deformation and breakout (Project 3) has far more applications than presented in this proposal. It has potential applications in civil engineering tunnels and borewell stability projects. Therefore, a technological breakthrough could find much broader variety of end users.