Characterizing behaviour of healed rockmass structures

在以特别深(500米)地下开挖和大型露天矿边坡为特征的现代贱金属采矿中，有效的岩土工程特征对于初始开挖和地面支撑设计以及在整个项目开发过程中准确预测岩体性态至关重要。大型露天矿和块状洞穴采矿法是开采大型矿体的流行方法，因为预计全球供需预测较高，生产率提高，工人安全得到改善。采矿业是新不伦瑞克和加拿大的重要产业；加拿大采矿业在全球13种主要矿物和金属的产量中位居前5名。2015年，整个行业为加拿大GDP贡献了560亿美元。 这项研究计划的主要目标是进一步了解地下开挖和岩质边坡周围的岩体结构愈合元素的行为及其对岩体行为的贡献。愈合的岩体结构，称为块内结构，发生在裂隙范围内的其他完整的岩石块内，影响岩石的变形能力和强度。在岩土工程项目的岩土工程勘察、表征和分析中，通常不考虑块内结构。然而，在特别是在高应力下的深部采矿挖掘中，人们观察到这些结构通过传统上被认为是完整的岩石或可预测的、自然破裂的岩石来控制地面破坏的额外或延迟发展。这些意外的地面故障需要在反应的基础上增加地面支持，这增加了工人的安全风险以及项目地面支持成本。随着挖掘的继续深入，裂隙对岩体性状的影响将变小，但块内结构没有深度限制，将对稳定性、安全性和矿山经济产生越来越大的影响。 这项研究计划将重点放在块内结构及其与地面行为的关系的现场检查，力学性质的实验室分析，以及融入岩土工程设计应用的数值模拟。指导这项研究短期目标的主要主题包括开发一个全面的区块内结构数据库，改进岩土数据收集和样本选择方法，对具有区块内结构的岩石进行岩土实验室测试，以及将区块内结构纳入先进的不连续介质数值模型，以预测大型露天矿边坡和块状洞穴矿山深部开采周围的深部破坏的岩体行为。 1名博士、4名硕士和5名URA将在DG研究计划期间接受培训，并将在工业界和学术界获得重要的曝光率。

In modern base metal mining featuring particularly deep (>500 m) underground excavations and large open pit slopes, effective geotechnical characterization of the rockmass is critical to the initial excavation and ground support design, and to the accurate prediction of rockmass behaviour throughout project development. Large-scale open pit and block cave mining methods are popular approaches to exploit large orebodies due to the high projected global supply and demand forecasts, increased production rates, and improved worker safety. Mining is a significant industry in New Brunswick and Canada; the Canadian mining industry ranks in the top 5 countries in global production of 13 major minerals and metals. The entire industry contributed $56 billion to Canada's GDP in 2015. The primary objective of this research program is to gain further understanding of the behaviours of healed elements of rockmass structure and their contributions to rockmass behaviour around underground excavations and rock slopes. Healed rockmass structures, termed intrablock structures, occur within fracture-bounded blocks of otherwise-intact rock, which influence rockmass deformability and strength. Intrablock structures are not conventionally considered during geotechnical investigation, characterization and analysis in rock engineering projects. However, in particularly deep mining excavations at high stress, these structures have been observed to control additional or delayed development of ground failures, through what is traditionally considered to be intact rock, or a predictable, naturally-fractured rockmass. These unexpected ground failures require additional ground support on a reactive basis, which increases the safety risk to workers as well as project ground support costs. As excavations continue to go deeper, fractures will have less influence on rockmass behaviour, but intrablock structures have no depth limit and will have increasing effects on stability, safety, and mine economics. This research program will focus on the field examination of intrablock structures and their relationship to ground behaviour, laboratory analysis of mechanical properties, and integration into numerical simulations for geotechnical design applications. Major themes to direct the short-term goals of this research include development of a comprehensive intrablock structure database, improvement of geotechnical data collection and sample selection methodologies, geotechnical laboratory testing of rock with intrablock structure, and the integration of intrablock structure into advanced discontinuum numerical models for rockmass behaviour prediction of deep seated failures in large open pit mine slopes and around deep excavations in block cave mines. 1 PhD, 4 MSc and 5 URAs will be trained during this DG research program and will gain significant exposure in industry and academia.