The Design and Construction of a Faced Symmetrical Hardfill Dam

Faced symmetrical hardfill dams represent a particularly robust and cost-effective form of construction, especially at sites where foundation conditions would not normally support a conventional concrete dam, but where the flood risk requires a structure capable of being overtopped. Extensive use of hardfill, using cement bound as-dug material, was made at the repairs to Tarbela reservoir in Pakistan in the 1970s, but by the 1980s the focus had moved to the production of roller compacted concrete (RCC) and processed aggregates. Concrete gravity darns, even to heights of 100 m, are generally stressed to levels far below those requiring structural concrete. A sloping upstream face to the dam to attract a vertical, upstream water load produces a very even stress distribution over the foundation, effectively eliminating upstream tensions. The broad design and construction concept for a FSHD is based around concrete gravity dam and RCC practice.