Table 2: Civil works (arch dam, underground powerhouse etc.) – Lot 1B/2/3

Arch dam – Features Dimension/Quantity Unit
Height 188 m
Crest length 420 m
Crest elevation 1,145 m
Maximum thickness at base 28 m
Thickness at crest 5.6 m
Low level outlet radial gates – 4 No. at el. 1,057m 8.0 x 5.6 m
Open excavation 310,700 m3
Underground excavation 14,800 m3
Concrete (mass and structural) 1,034,000 m3
Unit Cost of Concrete (incl. cement, not forms) $100.24 USD
Reinforcing steel 7,000 tonnes
Embedded cooling pipes 204,000 m
Concrete placement period 36 months
Maximum concrete placement rate 46,800 m3/month
Average concrete placement rate 28,700 m3/month
Cement Content (Dam mix including pozolans) 240 kg/ m3
Average dam concrete strength (150mm maximum aggregate mix – 97% std. dev.) 30.2 Mpa
Power Complex – Features Dimension/Quantity Unit
Intake structure height 75 m
Upper headrace tunnel, 7.25m lined diameter 320 m
Vertical shaft, 6.75m lined diameter 120 m
Lower tunnel 6.75m reducing to 4 – 4.0m steel lined penstocks 408 m
Powerhouse cavern 95lg x 18w x 38h m
Tailrace tunnels, 4 No. x 5m diameter x 73m long 292 m
Francis Turbines 4 ea
Plant Maximum Flow 220 m3/sec
Unit Design Head 155 m
River Diversion Works – Features Dimension/Quantity Unit
Diversion Tunnel No.1 – invert lined, dia. 7.8m 430 m
Diversion Tunnel No.2 – fully lined, diameter 7.0m 370 m
Upstream cofferdam – Mass concrete
Crest length 75 m
Top elevation 978.5 m
Height 18.5 m
Concrete Volume 10,443 m3
Tunnel No. 2- Duel High Pressure Bonneted Slide gates 2.54w x 2.67h m