Research on staged-filling scheme about concrete-faced rockfill dam of Hongjiadu hydropower station

The maximum height of the concrete-faced rockfill dam of Hongjiadu hydropower station is 179.5 m and the dam crest length is 427.79 m. The maximum streamwise width of dam foundation is 500 m. The total filling quantity is 9 million m~3, with fill intensity of 0.3 million m~3 per month on an average, and only one access way to the dam was available in 90% of filling construction period. The field condition of the dam determined that full section filling and rising of dam cannot be realized and the filling construction and retaining water in flood season should be carried out in stages. The cracking of bedding material and cracking and separation of face slab from bedding material have close relation to filling-stage division and filling velocity of the dam, reasonable filling scheme can avoid or greatly reduce the possibility of tensile and bending cracks of face slab. Through repeated scheme comparison and computation of the concrete faced rockfill dam of Hongjiadu hydropower station, and on the base of experience and lesson summarization on Tianshengqiao hydropower station, the reasonable staged-filling scheme was designed and it was predicted that the crack problem of the concrete faced rockfill dam of Hongjiadu hydropower station was minor.