The 130-ft high embankment at Selset Reservoir has been successfully constructed of clay of low permeabilhy in an area of high rainfall by using closely spaced drainage blankets to reduce the high pore-water pressures set up. Sand drains have been used to accelerate the consolidation of zones of soft clay in the foundation.
Extensive field observations of Dore-water Dressure. both in the fill and in the foundation, have been made as a control measure during construction. The estimates of pore pressure made at the design stage are reviewed in the light of the results.
The rise in groundwater level downstream of the cut-off on impounding has also been recorded. The effect of the resulting uplift on the stability of the downstream slope and south abutment, and itsc ontrol by relief wells, are also discussed.
