2022 – Defensive CFRD Embankment Design using Dirty Rockfill in a High Seismicity Environment – Waimea Dam

Brian Benson – Damwatch Engineering Ltd, Karina Dahl PhD – Damwatch Engineering Ltd, Peter Amos – Damwatch Engineering Ltd, Iain Lonie – Waimea Water Limited

Design and construction of CFRDs has evolved for over 100 years. Considered an ‘inherently stable’ dam type for decades, based on the principle of rockfill’s high drainage capacity and strength, CFRDs with poor rockfill challenge this presumption. This paper will present the design challenges posed from dirty, low strength rockfill for a CFRD in a high seismicity environment. Then it illustrates the use of defensive measures to augment CFRD performance to meet current societal safety expectations. For those CFRDs constructed of poor rockfill or in high seismicity environments, the reader will take away an appreciation of vulnerabilities and defensive measures to improve performance.