This design-build-operate-maintain-finance (DBOMF) project rebuilt a 10-mile stretch of Interstate-70, adding one new tolled express lane in each direction, removing the aging 54-year-old viaduct, lowering the interstate between Brighton and Colorado Boulevards, and placing a four-acre park over a portion of the lowered interstate. The design, submitted by Kiewit as a preferred alternate and selected by the client, will be constructed with a life expectancy of 75-100 years.
Central 70 is an iconic revitalization of a highway corridor in Denver, Colorado, that, to date, has exceeded its capacity, functionality and service life. The project scope includes constructing a 10-mile stretch of I-70 East, adding one new tolled express lane in each direction, removing the aging 54-year old viaduct, lowering the interstate between Brighton and Colorado boulevards and placing a 4-acre park over a portion of the lowered interstate. When completed, C70 will reduce congestion, improve safety and better accommodate future growth along the vital I-70 transportation corridor.
By working with the general contractor to develop a unique payment curve and optimizing the utilization of external financing and milestone payments, Kiewit successfully eliminated the need for short-term financing which ultimately saved over $18 million for the client. The project received Community Impact of the Year Award from American Road & Transportation Builders Association (ARTBA) in 2019 and Gold Awards in the Best Road/Bridge/Tunnel Project category and the Best Financial Structure category at the P3 Awards in 2018.
Kiewit Foundations performed approximately 1,123 drilled shafts, 615 grout columns and 32 secant pile shafts. Drilled shafts ranged from 42-inches to 60-inches at depths of 32- to 60-feet deep to help support a retaining wall for lowering the interstate between Brighton and Colorado Boulevards.
Kiewit also performed deep soil-mixed columns ranging from 2 to 8 feet in diameter for a complex storm and sewage drainage system below the water table.