Ground control strategies for burst prone mines

随着加拿大矿藏不断深入，人们更加重视地面控制措施，以处理由于高地应力导致各种形式的灾难性岩石破坏的岩石不稳定问题，如应变冲击、矿柱冲击和断层滑动冲击。这项研究计划的长期目标是帮助开发实用工具，帮助采矿作业采取适当的地面控制措施来减轻和控制冲击地压。短期内，这项研究计划包括以下五个研究项目。 第一个项目(MSC 1)研究了大型面板卸压爆破，这是在矿柱受到高度应力时使用的。该项目旨在优化主要设计参数，即1)矿体接触与盘区之间的距离，2)爆破盘区宽度，3)盘区超出矿柱界限。方法论以实地数据的数值模拟和分析为基础。 项目2(PHD 1，UG 1至3)试图调查一系列加拿大矿山坚硬岩石的内在性质。其目的是更好地了解岩石的内在性质，如粒度和矿物组成对岩石爆破行为的影响。这项工作包括使用扫描电子显微镜、粉末X射线衍射、粒子流动程序模拟(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井眼变形和崩落。其目标是开发一种方法来估计采矿引起的应力，以帮助就地面控制战略做出明智的决定。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的方法，另一种是基于强制突破的方法。该方法包括CAD设计和制造、数值建模、实验室和现场测试。 项目4(MSC 2)中的实验室和项目5(MSC 3)中的现场探索了在载荷下开槽钻孔以减少周围应力的概念。其目的是为了找出钻孔切槽是否可以成为一种通过钻孔自压裂来局部消能的实用方法。这项工作包括实验室和现场测试以及数值模拟。 作为全球矿产生产国，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。这一研究计划为10名HQP提供了一个独特的培训机会，即2名博士、3名硕士和5名本科生。拟开展的井眼变形与崩落研究工作(方案3)的应用远比本方案所提出的多。它在土木工程隧道和井壁稳定工程中具有潜在的应用前景。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.