Figure 6 - (Photo top) July 2009 - Variable depth cantilevers extend out 192' to form a gentle arch over the rail yard while maintaining appropriate clearances for construction. (Photo courtesy of FIGG). Figure 7 - (Photo inset) July 2009 - Concrete segmental box girders cantilever over active rail tracks in the Pueblo Rail Yard. Once closure is made, this 378' span will be Colorado’s longest highway span. (Photo courtesy of FIGG).

The Colorado Department of Transportation’s new Fourth Street Bridge in Pueblo, Colorado is taking shape. Construction of the twin 1,137' long concrete bridges began on October 17, 2007 and is proceeding on schedule. Three of the four end spans and the majority of substructure work have been completed. In addition, the first cantilever was completed in June 2009. Cantilevers now extend over the 28 sets of active heavy rail tracks in the Pueblo Rail Yard, as well as the Arkansas River.

Concrete segmental balanced cantilever construction (Figs. 6 and 7) allows railroad operations and recreational use of the river to continue below. Slender piers create a minimal footprint and feature aesthetic features selected by the community. The new bridge will also include two lanes of traffic in each direction, with wide safety shoulders and a multi-use path, to provide a high-quality and sustainable solution for the community.

Owner: Colorado Department of Transportation
Designer: FIGG
Contractor: Flatiron Intermountain Constructors
Construction Engineer: FINLEY Engineering Group, Inc.
Construction Engineering Inspection: FIGG
Pier Formwork: EFCO and DOKA
Form Travelers for Cast-in-Place Segments: VSL
Post-Tensioning Materials/Stay Cables: VSL
Bearings and Expansion Joints:
Joints - Watson Bowman Acme - A BASF Company;
Bearings - The D.S. Brown Company
Prepackaged Grout: Sika Corporation