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

该项目旨在协助大深度（>2km）的矿山和通过崩落作业开采低品位矿体的矿山。崩落允许大量开采边际和大型矿体，并且越来越多地被加拿大的采矿公司采用（例如，Afton和可能的Diavik矿）和世界各地。拟议的研究将集中在有效的，可变形的地面支持支柱设计。经验表明，安装在硬岩柱中的支撑通常是无效的，因为支撑系统不能管理由膨胀、破裂的岩石施加的大变形。研究人员将与提供支助的赞助者合作，开发有效的工具和技术，通过有效的支助改进界桩的设计和性能。建议重点关注三项紧迫任务：（1）基于变形的支护选择：使变形需求与支护的屈服能力相匹配;（2）抗变形支护部件的开发：包括评估混合螺栓作为可变形支护系统的潜在最有效螺栓;以及（3）随时间变化的支柱载荷：调查放矿点内和放矿点上方破碎岩石压实过程。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护能力，才能为采矿顺序和出矿策略提供有效和高效的支护。研究方法包括对物理模型试验结果进行反分析;对开采水平支柱进行现场监测;以及对加固应力断裂地面的分析和数值模型开发支持的混合岩石锚杆进行现场测试。调查结果将有助于在具有成本效益的支助下实现安全和更经济的支柱规模。研究将有利于加拿大矿山的财务和安全绩效，提高对应力地面设计的地球工程原理的理解，并为劳伦特大学的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.