Assessment of liquefaction potential of unsaturated oil sand tailings subjected to future saturation

未来饱和状态下不饱和油砂尾矿的液化潜力评估

• 批准号: 531144-2018
• 负责人: Sadrekarimi, Abouzar
• 金额: $ 1.69万
• 依托单位: University of Western Ontario
• 依托单位国家: 加拿大
• 项目类别: Collaborative Research and Development Grants
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=698052
• 关键词: Assessment; liquefaction; potential; unsaturated; oil

Oil sand tailings are by-products of the bitumen extraction process from oil sands, which include water, sand, fine particles, residual bitumen or other hydrocarbons. Large amounts of oil sand tailings are produced by the Canadian mining industry which are stored permanently behind large tailings dams. Liquefaction flow failure of a mine tailings dam and uncontrolled release of tailings would have a catastrophic impact on production, the environment, public perception, and loss of life. Safe and responsible management of these tailings requires proper understanding of their shear strength and resistance to liquefaction. However, liquefaction behavior and strength loss of oil sand tailings, either through earthquake loading or other triggering mechanisms such as rainfall, saturation, construction loads, or oversteepening of dam slopes are not well understood. In particular, the effect of partial saturation on in-situ test measurements and interpreting undrained shear strength of tailings is unknown. The proposed research will calibrate a widely used in-situ testing tool, the Cone Penetration Test (CPT), with strength, stiffness, unit weight, and fines content of saturated and unsaturated oil sand tailings. A comprehensive program of laboratory CPT model experiments, shear wave velocity measurements, and direct simple shear tests will be carried out on oil sand samples. The results will produce new knowledge in shear response and liquefaction behavior of oil sand tailings. A robust method will be established to predict in-situ strength, and liquefaction susceptibility of oil sand tailings under dynamic and static loads from CPT measurements. Mining engineers can then use this method in unsaturated oil sand tailings to assess the liquefaction potential and stability of tailings dams if they become saturated. This will allow mine operators and engineers to design safer tailings disposal dams and have a better understanding of the risks to existing dams. It will further benefit Canada, and particularly Alberta to minimize environmental risks of mining by ensuring that the mine deposit is ultimately integrated with the surrounding area and reclaimed into an environmentally-friendly and safe ecosystem.

油砂尾矿是从油砂中提取沥青过程中的副产品，其中包括水、沙子、细颗粒、残余沥青或其他碳氢化合物。加拿大采矿业产生大量油砂尾矿，这些尾矿永久储存在大型尾矿坝后面。尾矿坝的液化流动失效和尾矿不受控制的释放将对生产、环境、公众认知和生命损失产生灾难性影响。对这些尾矿进行安全和负责任的管理需要正确了解其剪切强度和抗液化能力。然而，油砂尾矿的液化行为和强度损失，无论是通过地震荷载还是其他触发机制，如降雨、饱和度、施工荷载或大坝坡度过度陡峭，尚不清楚。特别是，部分饱和对原位测试测量和解释尾矿不排水剪切强度的影响尚不清楚。拟议的研究将校准广泛使用的现场测试工具，锥入度测试（CPT），包括饱和和不饱和油砂尾矿的强度、刚度、单位重量和细粉含量。将对油砂样品进行实验室 CPT 模型实验、剪切波速度测量和直接简单剪切试验的综合计划。研究结果将为油砂尾矿的剪切响应和液化行为产生新的认识。将建立一种稳健的方法，通过 CPT 测量来预测动态和静态载荷下油砂尾矿的原位强度和液化敏感性。然后，采矿工程师可以在不饱和油砂尾矿中使用这种方法来评估尾矿坝饱和后的液化潜力和稳定性。这将使矿山经营者和工程师能够设计更安全的尾矿处理坝，并更好地了解现有水坝的风险。通过确保矿床最终与周边地区融合并重新融入环保和安全的生态系统，最大限度地降低采矿的环境风险，将进一步有利于加拿大，特别是阿尔伯塔省。