Dam Seepage Sensing and Modelling

大坝渗流传感和建模

• 批准号: 543918-2019
• 负责人: Butler, KarlKE
• 金额: $ 1.8万
• 依托单位: University of New Brunswick
• 依托单位国家: 加拿大
• 项目类别: Collaborative Research and Development Grants
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=751053
• 关键词: Dam; Seepage; Sensing; Modelling

Earthen embankment dams are widely used to contain hydroelectric reservoirs, water supplies and wastes such as those produced by mining and oil sands operations. Concentrated water seepage through such dams must be avoided to prevent internal erosion of fine-grained materials and the development of piping - a major cause of dam failure. Although standards for dams in Canada are amongst the strongest in the world, best practices have progressed over time, and the need for improved seepage monitoring methods that can be applied to aging structures is recognized internationally. UNB and NB Power will design and evaluate, through field trials and modelling, three minimally invasive geophysical approaches for the early detection and quantification of concentrated water seepage. The project will be based at NB Power's Mactaquac Generating Station on the Saint John River near Fredericton, NB, which includes a 500 m long zoned embankment dam, completed in 1968, that rises 32 m above its toe. The methods will rely largely on monitoring of seasonal temperature variations within the dam, as measured directly using distributed temperature sensing (DTS), and indirectly by electrical resistivity imaging (ERI). Regions of higher seepage are expected to exhibit greater seasonal variations in temperature and hence resistivity as water from the dam reservoir moves through it. Zones of particular interest include the dam's clay till core and the left abutment where the dam adjoins a concrete diversion spillway structure that is undergoing differential expansion as a consequence of Alkali Aggregate Reactivity in the concrete. The former will be investigated using time-lapse 2D resistivity monitoring along the dam crest which has yielded encouraging results on similar dams in Sweden. The abutment region will be investigated in more detail using borehole DTS complemented by time-lapse 3D resistivity monitoring with electrodes on the back of the dam. The research will build on valuable insights obtained from prior monitoring research in the abutment region using DTS and self-potential (SP) methods. It will be applicable worldwide but particularly in regions such as Canada where seasonal temperature variations are large.

土堤大坝被广泛用于包含水力储层，供水和浪费，例如采矿和油砂行动产生的水。必须避免通过这种大坝浓缩的水渗漏，以防止内部细粒材料的内部侵蚀和管道的发展 - 这是大坝衰竭的主要原因。尽管加拿大的大坝标准是世界上最强的，但随着时间的推移，最佳实践已经取得了进步，并且在国际上可以确认可以改善可以应用于衰老结构的渗漏监测方法。 UNB和NB功率将通过现场试验和建模设计和评估三种微创地球物理方法，用于早期检测和定量浓缩水渗水。该项目将位于NB Power的Mactaquac Generating Station，位于NB弗雷德里克顿附近的圣约翰河上，其中包括1968年完成的500 m长的Zoned Ressankment大坝，该大坝在其脚趾上方32 m上升。这些方法将主要依赖于使用分布式温度感测（DTS）直接测量的大坝内季节性温度变化，并通过电阻率成像（ERI）间接测量。随着大坝储层的水通过其移动，预计较高的渗漏区域会在温度上显示出更大的季节性变化，从而表现出电阻率。特别感兴趣的区域包括大坝的粘土直到核心和左台，在该区域毗邻混凝土转移溢洪道结构，该结构由于混凝土中的碱总反应性而在进行差异扩张。前者将使用沿坝冠的延时2D电阻率进行调查，这使瑞典类似的大坝产生了令人鼓舞的结果。将使用井眼DTS对基台区域进行更详细的研究，并通过延时3D电阻率进行补充，并在大坝后部的电极上进行电极。这项研究将建立在使用DTS和自势（SP）方法的先前监测研究中获得的有价值的见解。它将在全球适用，尤其是在季节性温度变化很大的加拿大等地区。