File: Detailed Slope Stability Analysis and Assessment of the Original Carsington Earth Embankment Dam Failure in the UK
ABSTRACT A 1225 m long, 35 m high zone earth filled embankment was being constructed from 1981 to 1984 from a British Regional Water Authority to regulate flows in the River Derwent in England. The Carsington Dam was planned to be one of the largest earth filled dams in Britain. Its reservoir capacity was 35 million m3 and the watertight element was Rolled Clay Core with an upstream extension of boot shaped and shoulders of compacted mudstone with horizontal drainage layers of crushed limestone about 4 metres apart and a cut-off grout curtain (Davey and Eccles, 1983). The downstream slope was 1:2.5 and the upstream slope 1:3. Fill placing began in May 1982 and took three summers, with winter shutdowns. In August 1983 a small berm was placed at the upstream toe to compensate for a faster rate of construction. Earth filling restarted in April 1984 and was one metre below the final crest level on 4 June 1984 when the upstream slope slipped (Skempton, 1985). Observations of pore pressure and settlement were made during construction at four sections and horizontal displacements were observed from August 1983. The Carsington Dam was almost completed on 1984. However, at the beginning of June 1984, a 400-m length of the upstream shoulder of the embankment dam slipped some 11 m and failed. At the time of the failure, embankment construction was virtually complete with the dam approaching its maximum height of 35 m. Horizontal drainage blankets were incorporated in both the upstream and the downstream shale fill shoulders. Piezometers had been installed and pore pressures were being monitored in the foundation, in the clay core, and in the ….. Read more in: http://www.ejge.com/2013/Ppr2013.515mar.pdf
