Pecos Bridge over I-70 Bridge Replacement - Denver, CO

Wilson & Company served as Colorado Department of Transportation’s (CDOT) lead consultant for the most significant Construction Manager/General Contractor (CM/GC) delivery and Accelerated Bridge Construction (ABC) project completed to-date by CDOT. 

The Denver project reconstructed the Pecos Street Bridge over I-70 and the interchange in a diamond configuration incorporating 2-Lane modern roundabouts at the ramp intersections with Pecos Street.

• In order to minimize delays to the 130,000 daily vehicles using I-70 through the interchange, CDOT decided to use ABC bridge “roll-in” technology

During the weekend closure, the existing Pecos Street Bridge was demolished, and replaced with the new bridge. The roll-in moved the new structure from the bridge farm to the middle of I-70, rotated it 180 degrees, then moved it 800 feet down I-70 and placed it on its permanent abutments. The bridge was moved using four-lines of Self Propelled Modular Transporters (SPMTs). The move was completed and I-70 was opened to traffic 4.5 hours ahead of schedule.

Fast Facts:

• The project received federal “Highways for Life” funding with the ABC commitment to, as stated by U.S. Secretary of Transportation Ray LaHood, “…allow the bridge to be put in place all at one time over a 50-hour period, instead of disrupting traffic over twelve months.”  
• The complexity and associated risks of rolling a 5 million pound bridge structure into place on I-70 over a weekend ideally suited the project for CM/GC delivery
• Using CM/GC delivery, CDOT, and Wilson & Company were able to integrate the contractor’s methods and means into the project design to provide the most innovative solution to address the project complexity and reduce construction risks.
• The complex bridge design included the permanent bridge along with associated temporary structures necessary to construct the structure off-site in a bridge farm, and then move the bridge into its permanent location
• To accommodate the roundabout intersections the 156-foot long single span bridge was an hourglass shaped structure requiring a cast-in-place, post-tensioned concrete superstructure
• The bridge included more than 19 miles of post-tensioning strands                  
   

Pecos Bridge over I-70 Bridge Replacement archived blog posts