Portland International Airport Terminal Core Redevelopment Phase I Opens!

For over four decades, GRI has proudly partnered with the Port of Portland, providing geotechnical and pavement engineering services at Portland International Airport and the surrounding port facilities. Our long-standing relationship is built on a foundation of trust, reliability, and a shared commitment to excellence. Throughout these years, we have delivered tailored solutions that address the unique challenges of the Port’s diverse infrastructure needs, ensuring safety, sustainability, and performance across all projects. This deep collaboration underscores our background in supporting critical transportation hubs and highlights our integral role in the Port’s ongoing infrastructure development. To build upon this strong relationship, GRI supported the Port with their latest project, the Terminal Core Redevelopment.

The Portland International Airport (PDX) has been undergoing significant changes with the Terminal Core Redevelopment (TCORE) project, a major expansion aimed at improving passenger experience and modernizing infrastructure. This $2+ billion project is designed to support the long-term growth of the airport, by enhancing the user experience and improving public safety, especially during seismic events. With its strategic focus on resilience, the structure will be capable of withstanding a major earthquake along the Cascadia Subduction Zone, providing critical relief and services to the region in the aftermath.

Given the many complexities of this project, the design team knew that collaboration was a make-or-break element to drive the project’s success. To that end, the design team (including ZGF, KPFF, HNTB, PAE, and GRI) strived to foster collaboration using a temporary on-site office (COLO) where designers could work together, integrating with the construction team as well as the many stakeholders involved in the project. This proximity was beneficial as the stakeholders were many, and timely collaboration with the project would pay dividends in finding timely, cost-effective solutions as issues arose in this technically complex project. The project involved key stakeholders such as the Port of Portland (including their various departments – corporate, police, air operations, and security/badging); the FAA, TSA, airlines, and the terminal tenants. This collaborative approach fostered an environment where the team seamlessly integrated innovative ideas into the overall design and construction efforts.

The terminal expansion project posed the challenge of supporting the stability of new foundations while keeping airport operations running smoothly. To tackle this, GRI performed geotechnical, seismic, and pavement services for the project and collaborated with the team throughout construction. This project was unique, particularly given the scale of the structure and the complex seismic behavior of the liquefiable soils. GRI’s geotechnical team partnered closely with KPFF (the structural engineer) to perform advanced seismic modeling of the soil-structure interaction to evaluate the dynamic performance of the foundation system, which was essential for the elimination of grade beams as well as evaluating differential behavior over a relatively long structure. GRI evaluated how complex subsurface conditions would influence structural behavior during both normal operations as well as during/following seismic events. The design process accounted for varying soil layers, seismic loading, and potential ground displacement, which were critical in designing foundations capable of mitigating risks like liquefaction and excessive settlement. In addition to the planned final design, GRI supported the project team in evaluating the temporary loading conditions for the existing foundation system during the roof jacking phase. This included both initial modeling of the foundations as well as precision monitoring with instrumentation during the roof erection. These items were critical in providing both a safe and cost-effective design and construction process.

The TCORE project will not only enhance passenger flow but also future-proof PDX for decades, preparing the airport for the challenges of climate change and increased seismic activity.

The second phase of the Terminal Core Redevelopment is slated for completion in early 2026.

This project was awarded the ACEC Oregon Engineering Excellence Grand and People’s Choice awards.

Thank you to our partners on a very successful project: Port of Portland, ZGF Architects, KPFF Engineers, HNTB, PAE Engineers, and Hoffman Skanska Joint Venture.