Yerba Buena Island (YBI) Tunnel (Segment 20) - Contract No. 04-0434L4:
Work consists of installing a grid of rock bolts at the arch head walls spanning the portals and catchment walls at each portal. Additionally, a rock slope adjacent to the west portal will undergo rock bolting to prevent small wedge failures.
The PS&E for Project 20 has been submitted to the Headquarters Office Engineer.
Rock bolting at the tunnel portals will require the obtainment of a license from the U.S. Navy. Additionally, the U.S. Navy must concur with the Categorical Exclusion of the project.
The YBI Tunnel (Segment 20) is scheduled for completion in the Summer of 2000.