Seattle’s Alaskan Way Viaduct Replacement Program contractor, Seattle Tunnel Partners JV, resumed mining on July 18th following a month of routine and hyperbaric maintenance on Bertha, the 57.5ft diameter Hitachi Zosen EPBM being used to bore the 2.7km long road tunnel. The move has allowed Client, the Washington State Department of Transportation (WSDOT), to review and publish the program and cost implications for the entire project.
Crews inspected and repaired machine components as needed during the maintenance period, which started on June 23.
The maintenance period included more than 40 shifts of work under hyperbaric conditions, changing cutting tools and performing other maintenance behind the cutterhead. In all, STP changed 33 of more than 700 cutting tools.
Tunnel boring is now one-third complete. The machine is located approximately 120 feet beneath Spring Street, tunnelling north toward First Avenue. At its deepest point near Virginia Street, the machine will be more than 200 feet below the surface.
STP expects to stop two more times for maintenance before reaching the future north portal, near the Space Needle.
After resuming tunnelling, STP updated their schedule, allowing WSDOT to do a preliminary review of the overall program schedule and budget.
The tunnel project is delayed, which has led to additional WSDOT costs, including for contract administration and oversight, says WSDOT in a project update. The costs to acquire right of way along the tunnel alignment have also been higher than originally projected, in part because of the need to extend agreements and leases. Upcoming construction projects, such as demolishing the viaduct, will have additional costs due to the tunnelling delay.
The legislatively-approved budget for the program is $3.1bn. Based on a preliminary review, WSDOT anticipates a 1.8 percent budget increase, or a cash-flow need of up to $60M in the 2017-2019 biennium, to ensure continued progress.
Looking toward completion of the viaduct replacement program, WSDOT says it estimates a total provisional budget need of $223M. That reflects a potential increase of 6.6 percent. These are preliminary estimates and WSDOT will continue to refine them as work progresses.
WSDOT has notified the Washington State Legislature of the program’s cash flow needs for the 2017-2019 budget cycle and will work with the Legislature through the budgeting process. The immediate focus according to WSDOT is addressing the up to $60M needed as a result of the tunnelling delay. The next 18 months of construction will tell a great deal about the program’s funding needs beyond the current biennium.
“We remain committed to completing this important safety project while also protecting taxpayers,” said Roger Millar, Acting Transportation Secretary, “We will continue to follow the terms of the design-build contract to recover the added costs that are due to the delay of the project.”
This includes pursuing insurance claims, identifying potential cost savings in other elements of the program and ongoing litigation to recover damages. If efforts to recover costs are successful, the funds would likely not be available until after the project is complete.
WSDOT will continue to provide additional details about the program’s budget needs as the 2017 legislative session approaches. In the meantime, the focus, according to WSDOT, will remain where it always has: on delivering the tunnel and replacing the Alaskan Way Viaduct for the people of Washington.