This project is nestled in Tukwila, Washington, and included the construction of approximately six miles of a new span-by-span and balanced cantilever precast segmental guideway structure. Founded on 10-foot-diameter drilled shafts and one mile of at-grade guideway, the structure called for self-fabrication of more than 2,500 precast segments, erected by a 500-ton gantry. The project scope included track work, handrails, systems integration components, and drainage provisions. The project also included one station with a park-and-ride facility, roadway corridor modifications with curbs, gutters, sidewalks, drainage, utility relocations, landscaping, and site restoration.
Working under high expectations from Puget Sound residents, the PCL team was under careful scrutiny to meet the project's environmental, schedule, and budgetary goals. While operating near some of the area’s most protected waterways and over some of its busiest highways, the team had to employ accelerated bridge construction (ABC) methods to minimize impacts. With the overhead gantry, the team safely erected the precast segments while minimizing the overall construction footprint. Utilizing a crane mounted on the guideway deck, the team constructed the segments without ground-mounted cranes to minimize impacts on the traveling public and the Duwamish waterway. When the client added nearly an additional mile to the contract midway through the project, the project team proceeded with an alternative erection method on a fabricated truss to meet the original schedule. The project team achieved project goals through imaginative construction practices, careful planning, and good communication with the client and stakeholders, making this one of the most successful projects on the initial Sound Transit Central Link line segments.