Rock Reinforcement for Extreme Underground Mining Ground Conditions

拟议的研究计划涉及管理极端地面条件的基本和应用研究需求：a)采矿引起的地震活动，以及b)大变形和挤压条件。岩爆是由采矿引起的地震活动引发的猛烈事件，导致大量岩石从地下挖掘的墙壁中喷出。它们可能是极其危险的，并对地下挖掘中的许多事故负责。巨大的变形和挤压的地面条件造成了重大的操作问题，往往需要对现有的支撑进行重大修复。 提出这一建议的依据是最近在加拿大矿山开展的以数据为导向的工作，这些工作查明了在极端地下采矿条件下管理地面控制问题方面的知识差距。可用于缓解深层地面控制问题的首批设计措施包括修改矿山设计布局、挖掘几何形状和挖掘顺序。这可以更好地控制采矿引起的应力，但不能缓解所有问题。第二项措施，也是这项建议的重点，是开发新的设计，以改善岩石加固和地面支持，以遏制和减轻这些极端的地面控制条件造成的损害，并确保采矿人员的安全和矿石的经济开采。 传统的设计方法没有考虑采矿诱发的地震活动、极端应力和构造驱动的变形对地面支撑的复杂加载机制。采用新的创新地面支撑(产出系统)提供了实实在在的好处。加固和支撑的冲击试验虽然不能捕捉加载机制或复制地雷诱发的地震活动，但为不同加固元件之间的比较提供了有用的工具。一个主要挑战是如何量化不同要素之间的载荷转移，以建立一个可以在地面支持设计中明确说明的“系统能力”。这项研究将依赖于对地面支持系统性能的实地和实验室调查。此外，还将对支撑系统进行三维数值模拟，重点放在加固和地表支撑构件之间的荷载传递机制上。 拟议的研究计划将为一些研究生提供一个独特的培训机会。他们都将与加拿大采矿业密切合作，并将获得独特的机会，发展高需求和多样化的技术技能。 在矿场实施拟议的研究将极大地促进矿工的安全，并在减少数亿美元的恢复和生产成本方面具有潜在的金钱影响。

The proposed research program addresses fundamental and applied research needs in managing extreme ground conditions: a) mining induced seismicity, and b) large deformations and squeezing conditions. Rockbursts are violent events, triggered by mining induced seismicity, that result in the ejection of volumes of rock from the walls of underground excavations. They can be extremely hazardous and have been responsible for many accidents in underground excavations. Large deformations and squeezing ground conditions result in major operational problems often requiring major rehabilitation of existing support. The formulation of this proposal is based on recent data driven work in Canadian mines that has identified the gaps in knowledge in managing ground control problems in extreme underground mining conditions. The first design measures that can be implemented to mitigate ground control problems at depth involves modifications to mine design layouts, excavation geometry and sequences of excavation. This can lead to better control over mining induced stresses but cannot alleviate all problems. The second measure, the focus of this proposal, is the development of new designs for improved rock reinforcement and surface support to contain and mitigate damage caused by these extreme ground control conditions and ensure the safety of mining personnel and the economic extraction of ore. Conventional design approaches do not consider the complex loading mechanisms on ground support due to mining induced seismicity, and extreme stress and structure driven deformations. The introduction of new innovative ground support (yielding systems) has provided tangible benefits. Impact testing of reinforcement and support, although not able to capture the loading mechanisms or replicate mine induced seismicity, has provided useful tools for comparisons between different reinforcement elements. A major challenge is how to quantify the load transfer between the different elements to establish a “system capacity” that can be explicitly accounted for in the design of ground support. This research will rely on field and laboratory investigations of the performance of ground support systems. These will be complemented by 3D numerical modelling of support systems focusing on the load transfer mechanisms between the reinforcement and surface support elements. The proposed research program will provide a unique training opportunity for a number of graduate students. They will all work closely with the Canadian mining industry and will have a unique opportunity to develop high in demand and well diversified technical skills. The implementation of the proposed research at mine sites will contribute significantly to the safety of mine workers and has potential monetary implications in mitigating rehabilitation and production costs amounting to hundreds of millions of dollars.