A constitutive model to analyse internal erosion in embankment dams

加拿大是世界上最大的水力发电国。与魁北克、马尼托巴、纽芬兰和拉布拉多以及育空地区一样，不列颠哥伦比亚省近90%的能源来自可再生水力发电。位于不列颠哥伦比亚省的贝内特大坝于1967年建成，是世界上最大的堤防大坝。三座水坝（班尼特水坝、米卡水坝和雷佛斯托克水坝）提供了该省一半以上的电力。它们代表了整个社会的巨大投资，而且，像我们的许多公共基础设施一样，这些堤防大坝正在老化，产生从水库渗水的潜在危险，侵蚀大坝及其基础内的土壤。内部侵蚀是大坝安全风险，在建设时没有被理解，现在被认为是大坝安全的最大风险之一。我们提议与卑诗水电公司（BCH）开展联合研究项目，以解决堤防大坝何时何地可能发生内部侵蚀的问题。我们将对堤坝的土壤进行实验室测试，并将结果与现已退役的库西尔大坝的法医观察结果以及班尼特大坝天坑事件周围的现场监测数据进行比较。我们将制定和校准一个本构模型，以分析在堤防大坝内部，侵蚀可能开始的地方，以及它的进展速度。考虑到加拿大各地地质过程和土壤形成的相似性，这些发现将与北方气候下的堤防大坝普遍相关，无论其大小或用途如何。我们提议的工作将使加拿大水坝部门受益，使其对水坝安全的承诺达到无可否认的世界级水平，并且适合这个世界上最大的水力发电国家。

Canada is the world's biggest producer of hydroelectric power. British Columbia, like Quebec, Manitoba, Newfoundland and Labrador, and the Yukon, generates almost 90 % of its energy from renewable hydropower sources. The Bennett Dam in British Columbia was, upon completion of construction in 1967, the largest embankment dam in the world. Three dams (the Bennett, Mica, and Revelstoke dams) generate over half of the province's electricity. They represent an enormous investment by society-at-large and, like much of our public infrastructure, these embankment dams are aging, yielding a potential for water seeping from the reservoir to erode soil within the dam and its foundation. Internal erosion is a dam safety risk that was not understood at the time of construction - it is now recognised to pose one of the greatest risks to dam safety.We propose a joint research project with BC Hydro (BCH) to address the questions of where, and when, internal erosion may occur in an embankment dam. We will perform laboratory tests on soil from embankment dams, and compare the findings with forensic observations at the now-decommissioned Coursier Dam, and with field monitoring data available around the sinkhole incidents at the Bennett Dam. We will formulate and calibrate a constitutive model to analyse where erosion can be expected to initiate, and at what rate it progresses, within the body of an embankment dam. Given the similarity of geologic processes and soil formation across Canada, the findings will be of general relevance to northern-climate embankment dams, regardless of size or purpose. Our proposed work will benefit the Canadian dam sector by placing its commitment to dam safety at a level that is undeniably world-class, and befitting of a country that is the biggest producer of hydroelectric power in the world.