Structural EngineerKPFF Consulting Engineers.
Text description provided by the architects. The new Tukwila Urban Center Bridge is adjacent to Bicentennial Park and crosses the Green River in Tukwila, a suburban city bordering Seattle at its northern edge. The watercourse flows out of the Cascade Mountains through communities in Washington state, and is important for salmon spawning and has traditionally been a tribal fishing river in the Pacific Northwest. The bridge has been designed to celebrate the history of the river, protect the local natural habitat, and create a new pedestrian connection between the commercial district in the west and the eastern part of the city.
The form of the 220-foot structure was inspired by tribal canoes and is defined by the 45-foot high bowstring arch and the 16-foot wide concrete deck. On the edges of the crossing path, the bridge dematerializes and opens to the water flowing below with stainless steel grills used to reduce shade and open the surface to sunlight. This design element enhances the natural flow of the river and is important in creating a bright, welcoming habitat for salmon to swim downstream on their journey to the Pacific Ocean, where they grow to become adults.
The simple form of the bridge reflects a balance between the human scale and the scale of the city, establishing a monumental presence that creates a new sense of place along the Green River Trail. The bridge is illuminated with LED lighting that can be modulated in different colors and light levels, creating a dynamic play of color.
The new Tukwila Urban Center Bridge conveys simplicity, clarity, and lightness. Moreover, the project is key to implementing the land use and transportation goals of the Tukwila Urban Center Plan and creates a safe and enjoyable walking and biking experience for the Tukwila community.