Improved Procedures for Analyzing the Deformation and Failure Responses of Brittle Rock in High Stress Environments

行业预测表明，未来几十年，随着可用资源的加深，地下大规模采矿作业的产量将大幅增加。这些作业的经验已经表明，在所考虑的深处遇到的岩体响应是复杂和严重的。这些都暴露了现有预测工具的局限性。从支架设计的角度来看，所涉及的高应力环境和复杂的应力路径超出了所依赖的经验设计工具所代表的经验基础。最近在我的研究活动中取得的成功已经确定了基于变形的支撑设计的必要性，其中涉及到诸如剥落等脆性破坏机制。然而，依赖于计算变形响应的数值工具主要是基于剪切的模型和体积膨胀的假设，而在剥落的矿柱中看到的过度膨胀明显指向伸展破坏机制和定向膨胀。为此，我们首次建立了脆性岩石的三维有限元强度动员模型和相应的三维定向膨胀模型。作为补充，我们开发了一种柱级规模的3-D粘结块体模拟技术，能够显式模拟开挖规模的脆性破坏和由于几何不相容而导致的岩石体积膨胀，包括不同的支撑策略对这些问题的性能响应。*为本发现基金提出的研究将在这些成功的基础上进一步促进我们对脆性岩石变形和破坏的理解，同时采取重要步骤来改进和验证我们开发的工具。这将通过研究目标实现，HQP将在岩石表征、岩石力学测试、矿山监测数据解释和高级数值建模方面接受实践和最先进的培训。总之，拟议的研究计划将有助于交付和促进新工具和知识的使用，这些新工具和知识更适合于应对加拿大矿山向更深层次发展时将遇到的挑战。将制定最佳实践准则，通过改进支撑设计战略，帮助更好地管理深部采矿应力和不利的岩体反应。与现有行业合作伙伴的密切合作将有助于确保研究成果(知识、工具、方法等)将被快速有效地转移，在缩短新技术研发及其实施之间的时间线上促进优化机会和提高安全性。HQP将学习加拿大资源行业非常需要的技能，这些技能对加拿大未来的自然资源开发需求具有战略重要性。**

Industry forecasts indicate that there will be a significant increase in production from underground mass mining operations over the next decades as available resources trend deeper. Experiences from these operations have already demonstrated that the rock mass responses encountered at the depths being considered are complex and severe. These have exposed limitations in existing predictive tools. From a support design perspective, the high stress environments and complex stress paths involved are outside the experience-base represented in the empirical design tools being relied upon. Recent successes in my research activities have identified the need for deformation-based support design where brittle failure mechanisms like spalling are involved. However, the numerical tools relied upon to calculate deformation responses are dominated by shear-based models and assumptions of volumetric dilation, whereas the excessive bulking seen in spalling pillars clearly point to an extensional failure mechanism and directional dilation. For this, we have developed a first-of-its-kind 3-D confinement-dependent strength mobilization model and associated 3-D directional dilation model for brittle rock. Complementing this is a pillar-scale 3-D bonded-block modelling technique we've developed capable of explicitly modelling excavation-scale brittle failure and rock mass bulking due to geometric incompatibilities when broken pieces of rock move relative to each other as they are squeezed into the excavation, together with the performance response of different support strategies to these.******The research proposed for this Discovery Grant will build on these successes to further advance our understanding of brittle rock mass deformation and failure, while taking important steps to advance and validate the tools we've developed. This will be achieved through research objectives that will see HQP trained in both the state-of-practice and state-of the-art in rock mass characterization, rock mechanics testing, interpretation of mine monitoring data, and advanced numerical modelling. Together, the research program proposed will help to deliver and promote the use of new tools and knowledge more suitable for the challenges that will be encountered as Canadian mines progress to greater depths. Best practice guidelines will be produced that will help contribute to better management of deep mining stresses and adverse rock mass responses through improved support design strategies. Close collaboration with existing industry partners will help to ensure that research deliverables (knowledge, tools, methods, etc.) will be quickly and effectively transferred, facilitating optimization opportunities and improved safety on a reduced time-line between R&D of new techniques and their implementation. HQP will learn skills that are in high demand in the Canadian resource industry and are of strategic importance for Canada's future natural resource development needs.**