East Link Extension

Stacy Witbeck constructed a 1.9-mile segment of Sound Transit’s new East Link Extension, the first light rail to serve the east side of Puget Sound in the Greater Seattle area. The project interfaced with five other East Link projects, including the Redmond Link Extension. Once all are completed, the 14-mile alignment will connect riders to downtown Seattle and SeaTac International Airport, as well as the Lynnwood Link Extension. 

Need 

Separated by a large body of water, congestion between the East side of Greater Seattle and the downtown area has been a notorious issue in the region. Once completed, the combined projects making up the East Link Extension, including E335 and Redmond, will provide passengers with a more convenient way to traverse throughout the city. 

Work 

• Retained cut/fill segments. 
• Major cast-in-place segmental bridge. 
• Four passenger stations, one being multi-level. 
• Waterlines, sanitary sewer, and storm drainage utilities. 
• Embedded, direct fixation, and ballasted track.  
• Turnouts, diamonds, and a double crossover.

Collaboration 

All construction was located in a dense urban environment, requiring complex logistics and phasing to mitigate impacts to the community and travelling public. Much of the work had to be performed at night to allow for delivery and setting of large precast girders. The team developed detailed traffic control plans necessary for road closures, including several complete closures of the major multi-lane I-405 freeway. 

Coordination with the downtown businesses and municipal facilities required constant communication to keep all parties apprised of the work taking place. As an example, the following took place in a single city block: 

• Excavation and shoring of a 40-ft deep, 50-ft wide cut-and-cover segment 
• Demolition of half an existing parking garage and part of the police department’s footprint,  
• Construct a major transit station with a transition to abridge across a freeway.  
• Maintain existing utilities across the cut-and-cover portion, including the 911 emergency phone system. This was done by suspending the utility lines above the excavation with support systems in place.

All of this work was performed directly adjacent to Bellevue City Hall, the police station, a Microsoft office tower, and the Meydenbauer Center – major entertainment and convention venue.