DFW International Airport Gate C Demolition and Replacement Project

The modular construction approach enabled the rapid completion of a new 80,000 square feet (7,432.24 m²) central concourse on a challenging site at Dallas-Fort Worth International Airport (DFW).

This project involved the demolition and replacement of four gates known as Gate C, located within Terminal C of DFW Airport. The new 80,000 square feet central concourse consists of six individual modular units, each approximately 84 feet by 84 feet (25.6 m x 25.6 m).

These modular units were constructed using traditional steel framing at a site one mile (1.61 km) away and were transported to the terminal construction site using Self-Propelled Modular Transporters (SPMTs). Once the modular units arrived on-site, additional steel framing was installed in the gaps between the modules. This method allowed for the simultaneous construction of the modular units while the original structure was being demolished and the foundations and support columns were being installed, resulting in a project timeline reduction of approximately 22%.

The structural design of each modular unit needed to meet the self-supporting requirements of the fabrication site while ensuring sufficient structural integrity and stability during transportation on SPMTs and once integrated as part of the central concourse. To facilitate this design concept, creative solutions were required for both the lateral and gravity load systems. Laterally, each modular unit utilized a combination of braced frames and moment-resisting frames to create a self-supporting module, maintaining stability. At the terminal construction site, these modules were connected, allowing multiple individual lateral systems to work collectively.

Throughout the fabrication and terminal construction phases, a traditional gravity load path was followed, where all loads are ultimately transferred from the floor to beams, and subsequently to columns and foundations. Some columns at the terminal construction site could only be installed after a modular unit was in place, as these columns were directly in the load path of the SPMTs. Each column was temporarily required to support a modular unit for a fixed period before the transporter had to return to the fabrication site to carry the next module. Due to these time constraints, the project team proposed a composite column concept, with the steel component designed to support the module on the SPMT. Once the steel column was positioned on-site, the transporter would unload the modular unit, and concrete would be poured around the steel column to form a composite column capable of bearing all lateral loads and building occupancy loads.

In addition to designing the beams for the central concourse to support the weight of the modular units during transport, the project team also analyzed potential overturning moments caused by wind loads or the deceleration of the SPMTs. The friction between the beams of the central concourse and the SPMTs helped prevent sliding of the modular units during transportation.

To further expedite the project schedule, the roof, exterior walls, metal panel systems, and curtain walls, along with various equipment ducts and piping, were installed within the modular units at the fabrication site. This required additional coordination and further structural analysis during the fabrication of these systems to ensure that any unforeseen deformations during transport would not damage the metal panel systems or glass curtain walls.