Ultrasonic and Acoustic Emission Imaging of Brittle Fracturing Processes to Investigate the Progressive Failure of Rock

脆性断裂过程的超声波和声发射成像研究岩石的渐进破坏

• 批准号: RTI-2019-00065
• 负责人: Eberhardt, Erik
• 金额: $ 10.93万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Research Tools and Instruments
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=649905
• 关键词: Ultrasonic; Acoustic; Emission; Imaging; Brittle

***Canada is facing a new generation of engineering challenges involving deep underground excavations and resource extraction. Several mines are approaching 3000 m depth resulting in excavations experiencing significant stress-induced brittle failure and rock bursting hazards. This has significant implications for mine designs, including safe and effective support. Canada's nuclear waste management program is now searching for a site for a deep repository with the geological conditions necessary to satisfy safety requirements. Assessing the potential for stress-induced brittle fracturing is essential for this as the resulting excavation damage zone may increase the permeability of the rock acting as a geological barrier by 2 or 3 orders of magnitude. Hydraulic fracturing operations to enable production from Canada's unconventional gas reservoirs have been subject to public, industry, and regulator concerns regarding induced seismicity. Growing concerns are heightened due to knowledge gaps in our understanding of fault slip mechanisms and the factors controlling the likelihood and magnitude distribution of events. The experimental equipment being requested in this proposal will help us to accelerate our research programs addressing these challenges, by allowing us to image and therefore improve our understanding of brittle fracture processes and ability to measure and quantify their effects on rock strength, deformation and permeability change. ******The equipment requested will leverage an existing state-of-the-art rock testing facility capable of simulating the high stresses, pore pressures and temperatures experienced deep within the Earth, while measuring rock stress, strain, and permeability change. To this, the requested equipment will add unique capabilities to detect and image the initiation of brittle fracture damage and its evolution through progressive rock failure. Specifically, this includes simultaneously conducting time-lapse ultrasonic velocity imaging of brittle fracture damage anisotropy and failure localization, as well as detecting the source locations and source mechanisms of the brittle fractures generated using acoustic emissions (AE). We have a proven track record in experimental rock mechanics that is amplified by our ability to integrate experimental results with field-based observations, state-of-the-art numerical modelling, and new 4-D holographic visualization. This synergy leads to both improved experimental design and more robust interpretation of results. We have published extensively on these topics, and the requested equipment will allow us to continue to build upon our previous research successes. Separately, the equipment will also create numerous opportunities for interdisciplinary collaboration involving colleagues studying the role and evolution of brittle fracture processes related to CO2 sequestration, geothermal energy, and earthquake, landslide and volcano hazards.**

***加拿大面临着新一代的工程挑战，涉及深层地下发掘和资源提取。几个矿山接近3000 m的深度，导致发掘，经历了严重的压力引起的脆性衰竭和岩石爆裂的危害。这对矿山设计具有重要意义，包括安全有效的支持。加拿大的核废料管理计划现在正在寻找一个站点的深层存储库，并具有满足安全要求所需的地质条件。评估压力引起的脆性破裂的潜力对于这对此至关重要，因为产生的发掘损伤区可能会使岩石作为地质屏障的渗透性增加2或3个数量级。水力压裂操作以使加拿大非常规天然气储藏的生产受到公共，工业和监管者对诱发地震性的关注。由于我们对故障滑移机制的理解以及控制事件的可能性和幅度分布的因素，人们的关注越来越大。本提案中要求的实验设备将通过允许我们形象形象并提高对脆性断裂过程的理解以及测量和量化其对岩石强度，变形和渗透率变化的影响的能力来帮助我们加速解决这些挑战的研究计划。 ********所需的设备将利用现有的最新岩石测试设施，能够模拟地球内部经历的高应力，孔隙压力和温度，同时测量岩石压力，应变和渗透率的变化。为此，要求的设备将增加独特的功能，以检测和图像脆性断裂损伤的启动及其通过渐进式岩石故障的发展。具体而言，这包括对脆性断裂损伤各向异性和失败定位的延时超声速度成像，以及检测使用声学发射（AE）产生的脆性断裂的源位置和源机制。我们在实验性岩石力学中具有验证的往绩记录，该记录通过我们将实验结果与基于现场的观测值，最先进的数值建模和新的4-D全息可视化的能力扩大。这种协同作用既可以改进实验设计，又可以对结果进行更强大的解释。我们已经广泛发表了这些主题，所需的设备将使我们能够继续基于以前的研究成功。另外，该设备还将为涉及同事的跨学科合作创造许多机会，以研究与二氧化碳，地热能量以及地震，地震，滑坡和火山危害相关的脆性断裂过程的作用和演变。**