Alaskan Way Viaduct Replacement Project

The State Route 99 tunnel, also known as the Alaskan Way Viaduct replacement tunnel, is a bored highway tunnel between Downtown Seattle and Lake Union, stretching two miles. It was deemed to be failing and the fear of an earthquake placed priority on a solution in 2009, due to the weak infrastructure.   

Services provided by Bravo:

• Tank Cleaning
• Pipe Jetting & CCTV Inspection
• Hydro Excavating
• Shaft Cleaning
• Water Leak Detection Monitoring
• Utility Settlement Point Installation
  

Bravo was on-site as a sub-contractor, but critically came in as a preferred vendor due to our Vactor Truck inventory when the project reached its high point.   

The biggest challenge on this project was when the drilling unit, “Big Bertha,” had a catastrophic mechanical failure, leaving it stranded 100’ underground. This delay lasted for more than two years as the workers had to dig a 120' (37 m) vertical shaft down to Bertha's cutting head, to repair it.

Bravo Environmental was mobilized to strategize a rescue plan to repair the drill in partnership with STP and Malcolm Drilling. Bravo was the sole-source vac truck company providing 24-hour service due to being the only company with the equipment capable of pulling such extreme distances. Our specialized vacuum trucks were pulling over 500’ in length and 100’ of head pressure—extreme and remote. 

Most vac truck companies lose vacuum at this length by investing in inferior vacuum trucks. However, we invest in solid equipment and we also designed and engineered the vacuum plan to remove spoils, so that the drilling head could be exposed, removed, and repaired.