11:56 PM: What was amnounced as a West Seattle Bridge “tour” with two city councilmembers and SDOT today was more of a visit and Q&A. We listened in as Councilmembers Lisa Herbold and Alex Pedersen talked with SDOT director Sam Zimbabwe and roadway-structures director Matt Donahue.
They looked at the underside of the bridge and its piers from two spots, near the entrance to the Jim Clark Marina parking lot, and a short distance west. A steady stream of trucks from Harbor Island provided enough constant noise that, at a safe social distance, we didn’t catch every word, but here are the highlights of what we could hear:
The discussion centered on the complexity of the task of determining how to stabilize and then repair the bridge. Donahue went into detail of the modeling that’s being used to analyze the cracks, which – as Zimbabwe told us in our April 2nd interview – continue to grow, though not at the rate that led to the bridge’s sudden shutdown 22 days ago. Cracking isn’t the only concern – parts of the bridge aren’t “sliding the way they’re supposed to.” (There’s more elaboration on the added concerns in this report by SCC Insight, which details a “locked lateral bearing” on Pier 18, the one in the next photo with a pipe running down it:)
He also explained that thoroughly understanding the problem is vital in designing the solution, because they have to take care that the stabilizing – including “shoring” – doesn’t get in the way of the ensuing repairs. All the while, they’re in a “race against time.”
What clues has the bridge’s past provided? Donahue noted he was in elementary school when the bridge was designed, but SDOT has “14 file cabinets” stuffed with documentation. The emphasis of current efforts, though, is the work being done by a “team of highly specialized (engineers),” consulting firm WSP, which has a deep portfolio of bridge work.
It was reiterated that the stabilization/shoring has to be done to make the bridge safe for major repairs – to get the cracks to stop growing.
So no new revelations, but the councilmembers do have a new perspective for when SDOT presents that moved-up briefing next Monday, which will mark four weeks to the day since the shutdown.
ADDED 11:02 AM WEDNESDAY: And we’ll get more new info even sooner – the mayor and various transportation officials plan a media briefing at 3:30 pm today.