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West Seattle Blog… | WEST SEATTLE BRIDGE: ‘Major milestone’ just reached in repairs

(Added: SDOT photo)

By Tracy Records
West Seattle Blog Editor

2:05 p.m.: The West Seattle Bridge is still on track to reopen in mid-September, and toward that, SDOT just announced a “major milestone” in bridge repairs – the “post-tension” steel cables to reinforce the bridge were tightened to 100%, and the bridge performed as predicted by the engineers’ calculations. We first learned of this during a conversation that just ended with the director of the bridge project Heather Marx, after requesting an interview to take stock of the repair work. She says the milestone was reached over the weekend. It’s not the last major part of the repair work – epoxy injection and carbon fiber wrapping continues – but it’s a big job. The project remains on schedule for the bridge to reopen “the week of September 12”, and Marx repeats that when they have 30 days to go, they will announce a more specific date. More information – including further updates to our conversation – to come.

ADDED 14:29: A slightly more technical explanation of the milestone – the monitoring installed on the bridge includes “instruments that tell us the shape of the bridge”, explains Marx, and the engineers have calculated what this shape should be when the post-tension is at 100% – so it was a big sigh of relief when they got to 100% and this form is exactly what resulted. The tension is done with cylinders which “pull (the steel cables) on both sides”, explains Marx. Email updates at the end of last week mentioned that they had reached 20%, and Marx says that was an important point along the way, to make sure it was going to work – “a while quality control”.

So what remains to be done to reopen the bridge that has been closed for 28 months? After the aforementioned final epoxy injections and carbon fiber wrapping – Phase 4, if you keep track – the CFR should cure, the work platforms will be removed and load testing will take place – “drive a truck at a specific weight, specific speed, back and forth” on the bridge, as well as other inspections. After all that, the restoration of the deck – all those notches in the concrete for the work platforms, for example – and demobilization, removal of work crews and equipment from the bridge, will follow.(They are already fixing the concrete – 60 panels of the bridge deck need to be replaced, and a week ago, says Marx, about 25 are finished.)

The fact that they’ve taken the major step of full post-tension doesn’t mean it all starts from here, Marx warns – “at the end of the project, the (possibility) of something unexpectedly going wrong remains at the same pace, so it’s a time of anxiety. But apart from the concrete delay, they have not experienced any other major blockages in recent times, she said – there is a shortage of cement at the moment , but they were able to work around the problem with the suppliers.

We had heard recently that SDOT does not allow a bridge run/walk/walk, one of the ideas that a community coalition has been pursuing, so we asked about that. Marx said they just didn’t want to risk an event being planned and the bridge being ready to open sooner, but they should keep it closed for an event – SDOT had long said that Once it was ready to open up, they wouldn’t let anything delay it a moment. So, we asked, is there any chance that you’ll announce after 30 days “the bridge will open on September X” and then find out as September X approaches that it’s ready to go someday ( or more) earlier? Marx said that was a possibility, but they expect the 30-day notice date to be as specific as possible. But “the general mood is (to open) as soon as the bridge is available.”

All this does not mean that there will not be an event related to the reopening; Marx says SDOT is planning one to thank the community for what they’ve been through. Free food the town will buy from local restaurants, and she’ll be there to help serve it. It’s not a celebration of SDOT, she points out, as they realize “the bridge is ours and it’s broken.”

We spoke with Marx about the work of the low bridge; more on that separately later.