Performance of culvert under Winscar dam

Earth pressures and settlements have been measured in the rockfill of a 53 m high dam on and adjacent to the crown of a rigid reinforced concrete culvert passing under the dam. The measurements were made under the highest part of the dam cross-section, where the culvert projected 3·8 m above the bedrock foundation into the rockfill. Compressibility of the rockfill was measured in a 1 m diameter oedometer and the results were used in conjunction with an analysis, using finite element techniques, to assess deformations and vertical pressure on the culvert. The measured values were in good agreement with those given by the analysis and at the end of construction the measured vertical pressure on the culvert crown was about 200% of the vertical stress to be expected in the rockfill in the absence of the culvert. There is good agreement with the original design assumptions and some measure of confirmation from photoelastic pressuremeters installed in the concrete. Les pressions des terres et les tassements ont...