Wekiva Parkway (Section 6)

Description

This project consists of three balanced cantilever bridges built with form travelers i.e. self-launching formwork machines that support themselves off the previously built segment to construct the next one. Construction Technologies & Engineering (CTE) was hired by Superior Construction, the general contractor on the project, to perform an independent design review of the form traveler. This required an accurate 3D model of the traveler to verify the structural adequacy in multiple situations and to determine the form traveler weight, center of gravity and reactions on the bridge as part of the camber calculations. A form traveler consists of three independent form systems, all supported by the same structural frame. In order to accurately set the form elevations for each pour, the traveler has to be analyzed as one complete, integrated system. These individual form settings are important because even small deviations from theoretical segment dimensions can have outsized effects on the bridge camber because of the cantilever amplification and the cumulative nature of segment deflections. In addition, CTE performed field inspections of the travelers before first use and reported back to the contractor with CTE’s findings and recommendations. There were also some special situations where Construction Technologies & Engineering helped the contractor with bridge closure pours using the form travelers, initial load testing of the form travelers and designing a scheme whereby the upper part of the form traveler was moved as a unit by crane from one bridge structure to the next.

How was RISA used?

Since Construction Technologies & Engineering project involvement wasn’t centered around routine building production tasks, they reserved RISA-3D for specialized projects. These include the realm of bridge construction equipment, the development of substantial civil temporary works, and various building repairs and rehabilitation initiatives.

RISA-3D proved invaluable in this recent endeavor involving form travelers, enabling precise modeling and design validation, encompassing the intricate formwork elements. While the majority of the model was constructed directly within RISA-3D using a stick-built approach, certain components were imported from CAD software. What sets RISA-3D apart is its remarkable speed and user-friendly interface. Results are attainable with remarkable swiftness, and the iterative process is notably expedited.

In CTE’s line of work, the steel code verification feature of the program has been a tremendous asset, offering invaluable assistance. The crux lies in comprehending the program’s full spectrum of capabilities and crafting modeling strategies that leverage these functionalities to their utmost potential.