Wayang dam project construction

The width of the valley bottom is only 10m, and it is expanded to 32m after excavation. Because the rock walls on both banks are steep and almost vertical, up to 300m, in order to prevent the rocks from slipping during construction, the ground surface was reinforced, and 4,700 m anchor rods and 30,000 cubic meters of steel wire mesh were used.

Considering the development of cracks in the upper rock mass of the dam shoulders on both banks, prestressed anchor cables are used for anchorage. Left bank 125, right bank 25, each 55m long, pre-tensioned 100t. For areas where the elastic wave velocity of rock mass is less than 3000m/s, consolidation grouting is used for reinforcement. The total length of consolidation grouting hole is 3700 meters.

The foundation treatment of Wayang Dam includes curtain grouting, consolidation grouting and contact grouting.

There are 2 rows of curtain grouting holes in dam foundation and 3 rows locally. The total curtain area is 80,000, the hole spacing is 3.5~4.5m, the row spacing is 1.5m, the grouting hole depth of dam base plate is 85m, the hole bottom extends to both banks 150m, and the hole top extends to both banks 60m. Grouting is carried out in 8 flat tunnels (4 on each bank), and the grouting pressure is 0.5 ~ 10 MPa.

The consolidation grouting hole depth is 15 ~ 25m, the bottom plate is arranged with 1 grouting hole every 6m, the grouting pressure is 0.2~2.5MPa, and the contact grouting requires 30m holes to be drilled for each meter of support. The total length of drilling holes in the whole grouting project is 654.38+600,000 meters, and the standard slurry consists of 50kg cement, 1 kg bentonite and100L water, with an average slurry consumption of 75kg per meter.

250kg/ m3 slag and pozzolanic cement are used for dam concrete, including clinker 160kg/ m3 and pozzolanic cement 90kg/ m3. The hydration heat of 28d is 60cal/g, the aggregate is natural gravel, the sand is Grade II, the powder below 0.006mm is removed, the aggregate is Grade IV, the maximum particle size is 102 mm, the water cement ratio is 0.44 ~ 0.46, and plasticizer and air entraining agent are added. The compressive strength of 90-day-old concrete is 35 ~ 42 MPa.

Concrete pouring is carried out by cable machine and 4 cubic meters hanging tank, and the small bulldozer is closed; Vibrate with a vibrator with a diameter of 125mm and a length of 90cm, and its vibration frequency is 1 1800 times per minute. Scour the solidified concrete surface with a feng shui gun. Within 72h, the pouring height is 2.4m at the bottom and 1.5m at the top. Layered casting thickness is 60cm at the bottom and 50cm at the top. The river water was cooled by the circulating system for 7 days.