Category: Monthly Webinar Colorado DOT’s Bronco Bridge over Platte River Replacement Project

November 7, 2019 1:00 pm

Ryan Sullivan-Hope, P.E., Region 5 Design Engineer and Asset Manager, Colorado Department of Transportation; Gregg Reese, P.E., Senior Technical Advisor, Modjeski and Masters, Inc.; and Q&A Panel member Andy Pott, P.E., Staff Bridge, Colorado DOT

Webinar Documents:
CDOT ABC Introduction - pdf of presentation
Bronco Bridge over Platte River Replacement Project - pdf of presentation
Q&A Session – pdf
News - November 7, 2019 - pdf of presentation

Description: The Colorado Department of Transportation’s new I-25 bridge over the Platte River near downtown Denver was constructed to replace the historic Bronco Arches which were built in the 1950’s as part of the initial I-25 construction. Completed in 2013, the new 371-ft-long and 197-ft-wide Bronco Bridge was constructed using ABC methods to replace the existing structure while minimizing impact to the 200,000 vehicles crossing the bridge each day. The precast superstructure was designed with an innovative combination of pretensioning and post-tensioning that complemented the construction scheme. The precast substructure design utilized integral abutments and piers that eliminated permanent bearings to reduce long-term maintenance. The distinctive arch-shaped piers give the bridge an aesthetic appear that is reminiscent of the steel arches in the original structure. Duration of each of the four construction phases ranged from 102 to 164 calendar days, greatly reducing the overall project schedule. The webinar will discuss design and construction details, lessons learned, and latest performance data.

Presentation Photos/Graphics:



1) Completed Project, Summer 2013

2) Bronco Bridge spanning across the Platte River and hike and bike trails and trolley line

3) Pile driving for abutments under existing bridge

4) Abutments cast under existing bridge to reduce impact to public

5) Precast pier erection

6) Precast girder erection

7) Girders erected with formwork and pre-tied reinforcing for diaphragms and anchor blocks


8) Full-depth precast deck panel erection