BEATING THE CLOCK

摘要

The Lake Oroville spillway's 400-acre construction site is an intense flurry of activity. In one corner, an excavator driver uses an old tire as a squeegee to clean away loose rock and prep a foundation. In the steeply sloping spillway chute, a crane operator flies in a rebar cage to workers who tie it into neighboring chute wall segments. Everywhere, dump trucks buzz around the circuitous roadways while rock crushers and batch plants keep pace with dozens of dozers and excavators. Drones hover in the sky photographing and surveying the site, while inspectors pour over every detail of the finished assets. Seemingly chaotic but actually highly choreographed and sequenced, the $1.1-billion Lake Oroville Spillways Emergency Recovery Project moves at an ultra-fast-track pace for one important reason: to repair the structures in time to protect cities, farmland and hundreds of thousands of people downstream of Oroville Dam before Northern California's rainy season begins in November. The scale of the task is immense. Once the spillways are complete, crews will have moved over 1 million cu yd of earth, cleaned 239,000 sq yd of foundation bedrock and crushed 2.3 million tons of aggregate-all in just 18 months.