Behaviour and support of highly stressed pillars in deep mines and caving operations

该项目旨在帮助大深度(&gt；2公里)矿山和通过崩落法开采低品位矿体的矿山。崩落法允许大量开采边缘和大型矿体，加拿大(例如Afton矿，可能还有Diavik矿)和世界各地的矿业公司越来越多地采用崩落法。拟议的研究将侧重于具有有效、可变形的地面支撑的矿柱设计。经验表明，安装在坚硬岩柱中的支架往往是无效的，因为支撑系统无法管理膨胀的、破碎的岩石造成的大变形。研究人员将与支助赞助商合作，开发有效的工具和技术，通过有效的支助改进支柱设计和业绩。建议将重点放在三项紧迫任务上：(1)基于变形的支架选择：将变形需求与支架的屈服能力相匹配；(2)抗变形支架组件的开发：包括评估混合锚杆可能是可变形支架系统最有效的螺栓；以及(3)随时间变化的矿柱加载：调查松散岩石在抽放点及以上压实的过程。只有更好地了解随时间变化的载荷需求、岩石变形行为和抗变形支架的能力，才能实现对采矿顺序和放矿策略的有效和高效的支持。研究方法包括对物理模型试验的结果进行反分析；对开采水平柱进行现场监测；以及对加固的应力破裂地基进行分析和数值模型开发所支持的混合锚杆的现场试验。调查结果将有助于在具有成本效益的支持下实现安全和更经济的支柱层面。这项研究将有利于加拿大矿山的财务和安全表现，提高对在受压地面设计的地质工程原理的理解，并为劳伦斯大学的HQP培训提供宝贵的机会。

This project aims at assisting mines at great depth (>2km) and mines extracting lower grade ore bodies by caving operations. Caving allows bulk mining of marginal and large ore bodies and is increasingly practiced by mining companies in Canada (e.g., Afton and possibly Diavik mines) and around the world. The proposed research will focus on pillar design with effective, deformable ground support. Experience shows that support installed in hard rock pillars is often ineffective because the support system cannot manage large deformations imposed by the bulking, fractured rock. The researchers will develop, in collaboration with the supporting sponsors, effective tools and techniques to improve pillar design and performance through effective support. It is proposed to focus on three pressing tasks: (1) Deformation-based support selection: matching deformation demand with the support's yield capacity; (2) Development of deformation resistant support components: including assessment of hybrid bolts as potentially the most effective bolts for deformable support systems; and (3) Time-dependent pillar loading: investigating processes resulting from compaction of fragmented rock in and above drawpoints. Effective and efficient support for mining sequences and draw strategies can only be achieved with better understanding of time-dependent load demand, rock deformation behaviour, and capacity of deformation-resistant support. Research approach includes back-analysis of results from physical model tests; in-situ monitoring of extraction level pillars; and in-situ testing of hybrid rock bolts supported by analytical and numerical model developments for reinforced, stress-fractured ground. Findings will assist in arriving at safe and more economic pillar dimensions with cost-effective support. Research will benefit financial and safety performances of Canadian mines, improve understanding of geo-engineering principles for design in stressed ground, and provide valuable opportunities for HQP training at Laurentian University.