Xibeikou CFRD
The dam is located in Yichang City, the first modern CFRD built in China. The maximum dam height is 95m with a crest length of 222m. It commenced construction in 1985 and completed in 1990, which was the pilot project of science and technology research program during 1985 ~ 1990. A series of technical and experimental works were carried out for this type of dam. The bed rock of the dam was limestone from which only gravel layers was excavated out within a range of 50m downstream of the plinth, and removing the surface from the rest part, retained layer was about 7m～8m as the dam base of rockfill body.
The bedrocks at both banks were cut into a slope of 10.5 and 10.8 the plinth base is on slightly weathered baserock.
The face thickness is 0.3m～0.6m with a vertical joint gap of 12m which was placed to the crest of the dam with a type of trackless slipform developed by the Chinese technician.
The total area of the slab is 27900 m2 with a largest slanting length of 147.03m, which was finished placing in 84 days. The perimeter joint sealing was arranged with 3 waterstops, copper waterstops installed at bottom, PVC waterstops in the middle and GB caulking material on the surface of the joint. The copper waterstops was installed at bottom and GB caulking material on the surface for the tensional vertical joints and only one copper waterstops for the compressed vertical joints
The reservoir was impounded to 1998, the measured maximum settlement of 369mm of the dam, the maximum settlement at dam crest of 61mm, slab deflection of 76.8mm, maximum normal displacement of 24.6mm and opening of 13.9mm at perimeter joint after impoundment. All the measured values are in the range of design. No abnormal leakage appeared after anti-seepage treatment at the right abutment.
Face cracking occurred during construction. Karst leakage also appeared at the right bank. The cushion layer was eroded by heavy storm and damaged by inverse seepage water. The dam has operated successfully up to now after treatment.
The pilot slab of face slab has had no cracks by now. The construction of Xibeikou CFRD provided successful experience for extension and development of CFRDs in China.
