Main spillway


and Canada. Within eight weeks, the full team of 125 staff and more than 500 units of equipment were on site, including a fully functioning concrete batch plant, a rock-crushing plant and a roller-compacted concrete (RCC) plant. Te team moved in 22 excavators, 10 cranes, 13 offroad trucks, 12 dozers and 12 loaders. It set up 35 trailers for offices and provided temporary water and power for all of its operations. Te team knew that once it was


given access to the main spillway, it had to be ready to begin demolition. Every minute counted.


165 DAYS On May 20, the countdown


clock began. Kiewit had 165 days to safely repair the main spillway for the next winter season — an extremely aggressive schedule considering the quantity growth since the original bid. To accomplish the challenge, the


team patched and reinforced the upper 730 feet of the existing spillway. An 870-foot section of the upper chute and 350 feet of the lower chute of the main spillway were completely demolished and reconstructed with steel-reinforced structural concrete to final design. Te original spillway incident left two large scour holes in the most challenging area of the chute. Tis 1,050-foot middle section was rebuilt with roller-compacted concrete, a sturdy, yet temporary solution to ensure the spillway could safely handle flows of 100,000 cubic feet per second (cfs). During Phase 2, crews will place permanent structural concrete on top of the middle chute’s RCC surface as part of the spillway’s final design, bringing the main spillway to final design capable of passing up to 270,000 cfs in case of extreme flood conditions.


HOT DAM With the world watching, the


countdown was on. “Dam cams” broadcasted construction activities live and drones were used daily to


www.AGC-CA.org


Phase 1: 350 feet of structural concrete


Lower chute


Phase 1 - May 15 - Nov. 1, 2017 Phase 2 - May 1 - Nov. 1, 2018


Phase 2: Demolish and replace 730 feet of original and repaired spillway with structural concrete


Upper chute


Phase 1: 870 feet of structural concrete


Phase 1: 1,050 feet of RCC


Phase 2: Remove and replace RCC walls with 1,050 feet of structural concrete on top of RCC surface


Middle chute


Phase 2: Hydro-blast and resurface energy dissipaters


Graphic courtesy of Kiewit


document the work. Crews worked around the clock to repair and recon- struct the main spillway. Before any concrete was placed, crews cleaned and vacuumed the foundation. Under normal circumstances, foundation cleaning is a labor-intensive job. Te hazards were amplified at


Oroville due to the 4:1 slope and an extreme, long-lasting heat wave where temperatures often exceeded 100 degrees. Shade tents helped combat the heat. Crews talked about the signs and dangers of heat stress, injuries and risks. Tousands of water bottles and crates of fruit helped maintain hydration, and Kiewit provided sunscreen packets to crews daily. Kiewit implemented a Craft Voice in Safety (CVIS) program, a time-tested Kiewit way to ensure craft employees can immediately and effectively raise


safety issues and take accountability for keeping each other safe. A medic was also stationed on-site in case of any unexpected medical issues. “Te safety focus on this project is


incredible,” Petersen said. “We had a very fast ramp-up and worked more than 780,000 man-hours, completing Phase 1 without a recordable injury. Our team works very hard to ensure nobody gets hurt on this project.” Northern California’s deadliest


wildfire season also affected the project. Smoke hindered visibility. Some employees’ homes were evacuated and one local fire had the project under an evacuation advisory. CalFire flew their planes across Lake Oroville to refill their water tanks, and work on the spillway continued.


TO THE WIRE Despite an aggressive schedule and Continued on page 18


Associated General Contractors of California 17


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24