Franklin Pacific Construction performed the structural concrete work on the Sound Transit North Gate Link Extension project. The structure consists of numerous retaining walls, sound walls, vehicle barriers, and a strutted portal. There was a total of approximately 4500 cubic yards of concrete on the project with nearly all of the finished concrete receiving a decorative form liner finish. The cantilevered retaining wall is approximately 240 feet long and varies from 5 feet to 21 feet tall. There is approximately 9000 square feet of sound wall that varies from 5 feet to 20 feet tall and 16,000 square feet of fascia wall construction over solider pile and timber lagging. The portal structure consist of approximately 390 lineal feet of 6 feet by 6 feet walers and 6 each struts that are approximately 54 feet long and 5 feet by 5 feet in section.
As the Maple Leaf Portal site is located at the north end of the railway tunnels and confined within a shored excavation that was approximately 45 feet deep the scheduling and coordination requirements of the project were numerous. Construction work within the tunnels was ongoing as Franklin Pacific built the structure so close coordination had to take place with the many other subcontractors working within the tunnels and using the Maple Leaf Portal as their primary access into and out of the tunnels. Franklin Pacific successfully completed this project on time and within the strict coordination requirements of the project. The cost of the structural concrete work for the Maple Leaf Portal was approximately $3.2 million which does not include the reinforcing steel which was supplied and installed by another Jay-Dee subcontractor.
GC: JCM Northlink LLC
Owner: WSDOT
Location: Seattle, WA