Photo courtesy of Edward Kraemer and Sons

The main flyover was constructed over State Highway 85, C-470 and two active rail lines.

2012 Best Project

Transportation Category

C-470 and Santa Fe Interchange Improvements

Littleton, Colo.

The C-470 and Santa Fe Interchange project included an 1,800-ft curved, post-tensioned U-girder bridge; more than 3,000 linear ft of cast-in-place and mechanically stabilized earth retaining walls; a 120-ft, single-span vehicular bridge; and a 120-ft, single-span pedestrian bridge. The main flyover was constructed over State Highway 85, C-470 and two active rail lines running through the project, increasing the logistical challenges of the job.

The Colorado Dept. of Transportation used an innovative delivery method that permitted bidding contractors to propose an alternate design for the 1,800-ft curved flyover. The project team developed the alternate bridge design during bidding and subsequently completed design and construction four months ahead of schedule and more than $500,000 below budget.

The project's use of precast pier caps resulted in an estimated savings of 1,890 man-hours and required 15 fewer nights of lane closures during construction than would have been required with the use of standard pier-cap forming.

The project's 13 pier caps were installed and grouted to the columns over eight working days. Standard construction would have resulted in approximately 30 to 40 working days to complete the task. This method was another major factor in completing the project four months ahead of schedule.

Key Players

Owner: Colorado Dept. of Transportation, Denver

Engineer: Tsiouvaras Simmons Holderness, Denver

General Contractor: Edward Kraemer and Sons Inc., Castle Rock, Colo.

Entry submitted by Edward Kraemer and Sons Inc.