A constitutive model to analyse internal erosion in embankment dams

点击翻译按钮获取中文摘要

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.