The Selmon Extension is a 1.9 mi toll lane located in the median of Gandy Boulevard, offering travelers a choice between using Gandy Boulevard for local destinations or the Selmon Extension for a direct connection eastbound to the Selmon Expressway or Dale Mabry, and westbound to the Gandy Bridge.
The Selmon West Extension viaduct, part of this project, spans over the existing Gandy Boulevard within the Interbay peninsula in Tampa. This elevated roadway bridge features a precast segmental superstructure with cast-in-place concrete fins over continuous piers, extending 1.3 mi (2.2 km) in length. Designed to limit its size while maximizing visibility, the superstructure elevates the toll lane to at least 30 ft, approximately twice as high as a typical urban bridge. The Selmon Extension enhances transportation safety for both local and regional travelers and provides reliable hurricane and emergency evacuation routes for the area.
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 of 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 adherence to project codes and standards. Additionally, the scope of work included verifying 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
Reseau Express Metropolitain (REM) – Greater Montréal, Canada
