1.800.595.5084 cx@glumac.com

Alaskan Way Viaduct / SR 99 Tunnel Replacement

Alaskan Way Viaduct / SR 99 Tunnel Replacement

Seattle, Washington
Size: 4-lane, 2 miles long
Construction cost: $4.25 Billion
End date: 2018
Architect: HNTB Architecture (part of Seattle Tunnel Partners joint venture team)
Design / Build Contractor: Seattle Tunnel Partners (Dragados USA and Tutor Perini Corp. joint venture)
Owner: Washington State Dept. of Transportation

Glumac, under contract to JH Kelly, is providing comprehensive commissioning services for the Replacement Tunnel project on the Alaskan Way Viaduct, a project that is currently under construction underneath downtown Seattle.

This tunnel was bored with the world’s largest tunnel borer, which has a 57.5 foot diameter, weighs 900 tons, cost $80 million, and is nicknamed “Bertha,” after Seattle’s only female mayor, Bertha Knight Landes.

The replacement tunnel carries approximately 110,000 vehicles per day to their destinations and allowed for demolition of the current viaduct structure, part of the transformative Seattle Central Waterfront redevelopment process.

Glumac provided and administered commissioning services for the systems serving both the tunnel itself and the operations buildings at each end. The data for each of these facility process systems travel through the central SCADA (supervisory control and data acquisition) system, which centralizes all functional testing that will be performed on the project.

Commissioned Systems

  • Mechanical, Electrical, Plumbing
  • Building automation
  • Illumination
  • Ventilation
  • Drainage
  • Fire suppression and smoke control
  • Toll readers
  • Signage
  • Carbon monoxide monitoring
  • Security systems
  • Communication systems, including telephone, cellular phone, two-way radio and AM/FM radio
  • Intelligent transportation systems, including a video-based detection system, used for detection of traffic that causes slowdowns or blockages, and CCTV