Sound Transit University Link Extension

The 3.15-mile University Link Light Rail line, completed in 2016, extended transit service from Downtown Seattle to the new underground Capitol Hill Station and ended at the new University of Washington Station located adjacent to Husky Stadium. A complex civil engineering and substantial, earth work effort involved three tunnel-boring machines operating for two+ years, with undercrossing at the Montlake Cut and tunneling beneath urban residential and commercial neighborhoods.

Greenbusch, as a subconsultant, provided the following professional engineering services:

- Acoustical Design: In support of the two new stations: Capitol Hill and University of Washington, performed acoustical modeling, analysis, and mitigation for audibility of the public address (PA) systems; acoustical finishes to control reverberant sound levels; and mitigation of mechanical system noise, including emergency tunnel ventilation, in both the stations and the surrounding communities.

- Noise and Vibration Consulting: Authored a Technical Noise Analysis and Recommended Mitigation Plan that served as a technical report appendix to Technical Noise and Major Public Project Construction Variances to allow for nighttime work on the site. The firm performed continuous construction noise monitoring start to completion, and supported community outreach.

- Audio/Video Engineering: Provided the Audio system designs, following the requirements of NFPA72, to serve the Capitol Hill and University of Washington stations and to ensure intelligibility of their PA systems.