Ground control strategies for burst prone mines

随着加拿大矿山不断深入到更深的矿床，由于高地应力导致各种形式的灾难性岩石破坏，如应变破裂、矿柱破裂和断层滑动破裂，因此越来越重视地面控制措施，以处理岩石不稳定问题。这项研究计划的长期目标是促进实用工具的发展，帮助采矿作业采取适当的地面控制措施来减轻和控制岩爆。在短期内，本研究计划包括以下五个研究项目。第一个项目（MSC 1）研究了大型面板应力爆破，这是在矿柱处于高应力状态时使用的。该项目旨在优化主要设计参数，即1)矿体接触面与底板之间的隔离距离，2)爆破底板宽度，3)底板延伸到矿柱界限之外。方法是基于数值模拟和现场数据分析。项目2 （PhD 1， UG 1至3）旨在研究一系列加拿大矿山硬岩的内在性质。目标是更好地理解岩石的内在性质，如粒度和矿物组成对岩石破裂行为的影响。这项工作涉及使用扫描电子显微镜、粉末x射线衍射、粒子流代码模拟（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破裂。目标是开发一种估算采矿诱发应力的方法，以帮助在地面控制策略方面做出明智的决策。该项目将测试和开发两种不同的方法——一种基于变形测量，另一种基于强制突破。方法包括CAD设计和制造，数值模拟，实验室和现场测试。在实验室项目4 （MSC 2）和现场项目5 （MSC 3）中，研究了在载荷下凿孔以减小周围应力的概念。目的是找出钻孔切迹是否可以成为通过钻孔自裂来局部耗散能量的实用手段。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，加拿大需要具有岩石工程、地下开采和岩爆控制方法知识和技能的HQP。该研究项目为培养10名HQP学生提供了一个独特的机会，即2名博士，3名硕士和5名本科生。拟议的钻孔变形和突破工作（项目3）的应用范围远远超过本提案。它在土木工程、隧道工程和井内稳定工程中具有潜在的应用前景。因此，一项技术突破可以找到更广泛的终端用户。

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.