Selmon West Extension – Tampa, Florida

The Selmon Extension is a 1.9-mile toll lane, located in the median of Gandy Boulevard, allowing travelers a choice to use Gandy Boulevard for local destinations or the Selmon Extension for a direct connection eastbound to the Selmon Expressway or Dale Mabry or westbound to the Gandy Bridge.

The superstructure is designed to limit its size while maximizing visibility. The toll lane will be at least 30 feet high, approximately twice as high as a typical urban bridge. The Selmon Extension provides safer connection transportation for both local and regional travelers and reliable hurricane and emergency evacuation routes for the Gandy area and regional residents.

SYSTRA IBT served as the Independent Checking Engineer, undertaking a crucial role in the project. In this capacity, SYSTRA IBT conducted an independent design review encompassing the foundations, substructure, and superstructure of three bridges. The examination involved cross-referencing information and criteria outlined in the design plans and specifications to ensure the design adhered to the project codes and standards. Additionally, the scope of work included the verification of the structure’s performance under service conditions.

SYSTRA IBT submitted comprehensive structural check reports for each of the examined elements. The following are the structures and structural elements checked:

Precast Segmental Viaduct

• Foundations (drilled shafts and foundation caps)
• Substructure (abutment, piers, pier caps, transition bent)
• Bearings
• Precast segmental superstructure
• Finbacks with PT tendons

Steel Box Viaduct

• Foundations (drilled shafts and foundation caps)
• Substructure (abutments, piers, pier caps, straddle bents)
• Bearings
• Steel box superstructure
• Cast-in-place concrete deck with transverse post-tensioning

Video credit: Tampa Hillsborough Expressway Authority