Fundamental Mechanism and Practical Implications of Residual Stress in Rock

虽然岩石是一种古老的建筑材料，但它的工程行为令人惊讶地复杂，仍然需要充分了解，特别是它的工程行为。残余应力（RSt）现象，即与材料形成相关的材料微观结构内的内部锁定应力的分布，已经在许多材料（例如，钢，包括岩石。虽然RSt已在岩石中观察到的现象还没有被量化或包括在用于工程分析的岩石行为模型。RST可能有实际意义的断裂形成和位移周围的高应力，大块岩层开挖。对于高水平的项目，如核废料的地质隔离，RST的实际意义可能是显着的预测周围的挖掘，这可能会影响污染物的运输断裂形成。 这项研究计划将检查和量化的RSt现象及其对岩石力学的影响。将进行一项研究，以检查RSt作为一个基本的岩石行为组成部分。由于直接观察微机械机制的复杂性，将使用一种综合方法，该方法将利用仔细监测的实验室实验，并使用微机械数值建模模拟进行解释。将在圆柱形钻芯试样中诱导（通常是热负荷）损伤（微裂纹形成），并将监测由于RSt释放引起的响应。同样，还将监测由于在岩石块试样中钻孔而释放的RSt，并增加热致损伤。为了量化RSt效应，将使用复杂的三维微观力学（基于岩石颗粒）数值建模来模拟实验。将通过观察到的实验响应与模型模拟行为的一致性来量化RSt的影响。研究结果将被用来开发一个岩石力学模型，其中包括以前忽视的RSt行为组件。RST岩石工程问题的实际意义，然后将探讨两个研究组成部分：1。RSt的应用，岩石损伤，核心盘和地下开挖周围的岩石稳定性的影响;和2。RSt在岩体开挖边界位移中的应用该研究计划的结果将有助于更全面地了解岩石破坏和位移的工程行为，并对采矿，土木工程和可持续能源项目中的地下开挖产生影响。 该研究计划将支持几个HQP的培训，包括一个博士，两个硕士和五个本科生，并将包括在实验室环境和使用先进的数值建模这两个在学术界和加拿大工业所需的技能培训。

Although rock is an ancient building material, it is surprisingly complex with engineering behaviour that remains to be fully understood, in particular its engineering behaviour. The phenomenon of residual stress (RSt), a distribution of internally locked in stresses within a material's microstructure related to material formation, has been identified in many materials (e.g., steel) including rock. Although RSt has been observed in rock the phenomenon has not been quantified or included in rock behaviour models used for engineering analysis. RSt may have practical implications to fracture formation and displacement around excavations in highly stressed, massive rock formations. For high level projects, such as geological isolation of nuclear waste, the practical implications of RSt may be significant in predicting fracture formation around excavations, which can potentially influence contaminant transport.   This research program will examine and quantify the RSt phenomenon and its implications to rock mechanics. A study will be conducted to examine RSt as a fundamental rock behaviour component. Because of the complexity of observing the micromechanical mechanisms directly, an integrated methodology will be used that will utilize carefully monitored laboratory experiments augmented with interpretation using micromechanical numerical modelling simulations. Damage (microcrack formation) will be induced (typically with thermal loading) in cylindrical drill core specimens and the response due to the release of RSt will be monitored. Similarly, RSt release due to drilling in a rock block specimen, augmented with thermally-induced damage, will also be monitored. To quantify RSt effects, sophisticated three-dimensional, micromechanical (rock grain-based) numerical modelling will be used to simulate the experiments. The effects of RSt will be quantified through reconciliation of observed experiment response with model simulated behaviour. The findings will be used to develop a rock mechanics model that includes the previously disregarded RSt behaviour component. The practical implications of RSt to rock engineering problems will then be explored in two research components: 1. The application of RSt to rock damage, core disking and implications to rock stability around underground excavations; and 2. The application of RSt to rock excavation boundary displacement. The findings of the research program will have implications in obtaining a more complete understanding of engineering behaviour of rock failure and displacement with implications to underground excavations in mining, civil engineering, and sustainable energy project.   This research program will support the training of several HQP including one doctoral, two masters and five undergraduate students, and will include training in both a laboratory environment and the use of advanced numerical modelling which are both skills needed in academia and Canadian industry.