Page - 1180 - in Book of Full Papers - Symposium Hydro Engineering

4. ENGINEERING PROJECTS EMPLOYING SPUC 4.1 CONSTRUCTION OF SPUC IN BOTTOM OF PILES IN TANJIANG BRIDGE The depth of the water is about 10 -15 m. The thickness of bottom concrete is 3.5 m. Area of concrete pouring is about 1000 m2, as shown in Fig. 4(a). The small circle with numbers denotes position of 31 designed trimies with a diameter of 300 mm. But only 24 trimies were used since the fluidity of SPUC is better than expected. 80% of consumed UPA was casted into the bottom water in workspace via tremies before concrete pouring started. Then 20% remained UPA was casted into a tremie and an insulate ball with a plug device are installed at the opening of the tremie. Concrete poured into water via the tremie after the insulate ball plugged. The end of the tremie was kept embedded into the concrete about 500 mm depth. The distance between tremies is about 8 m. The slope of concrete surface was about 1:20 – 1:30 during whole pouring process surveyed by measure ropes. (a) Layout of SPUC construction (b) Dilution and casting of UPA Fig. 4 Layout and casting of UPA in SPUC construction in Tanjiang bridge The whole process of SPUC construction lasted about 36 h smoothly. The total amount of SPUC poured is 2223 m3. The average compress strength of drill cores is about 40 MPa, higher than design value of 25 MPa. The construction of SPUC in Tanjiang bridge was very successful. 4.2 SPUC IN REHABILITATION OF WANYAO DAM Wanyao reservoir is a Large (Grade II) reservoir with irrigation, water supply, hydropower and flood control functions, which located in Jiangshan city, Zejiang Province, China [4]. The main dam of Wanyao reservoir is a Roller-Compacted Concrete gravity dam with a height of 79 m. The length of dam crest is 390 m. The whole dam is divided into 11 blocks, where Block 5 is spillway block and others are non-overflow blocks. During the poor construction quality, the dam has to be rehabilitated due to severe seepage problem. An impervious concrete face shall 1180