(ADDED 12:11 PM: WSDOT slide deck as presented to City Council this morning)
10:35 AM: The damage to the Highway 99 tunneling machine is “more extensive” than expected, but not more extensive than they were expecting to fix. That’s how it was just announced by WSDOT’s Todd Trepanier during the scheduled periodic Highway 99/tunnel project briefing for the City Council. For as long as the briefing continues, we’ve embedded it above (click the “play” button to access the live Seattle Channel stream). Trepanier specifically mentions machine sealing that’s been “stripped away.” Trepanier says Seattle Tunnel Partners hasn’t said what caused it, and doesn’t have to, under terms of the design/build contract, but councilmembers are pressing the point.
10:42 AM: First among them is Councilmember Mike O’Brien, who wants to know the schedule and says he’s nervous every day the Alaskan Way Viaduct stays open. Trepanier says that the contractor has told them they’ll have a revised schedule next month. Councilmember Tom Rasmussen asks if there’s some deadline for this to get going again; Trepanier says they want the contractor to “take the time that (they) need” but adds on followup that the contract does include deadlines with monetary consequences. Those deadline dates are not close, though, Trepanier says. He tries to move along but O’Brien asks again, do they have any idea what went wrong? Trepanier replies no, that’s between the contractor and the machine’s manufacturer. He continues showing images of the damage (no slide deck provided yet). “If everything is going wrong like this right now, how do we know (it’s OK) before it gets back in the ground (and resumes tunneling)?” asks Councilmember Sally Bagshaw.
Next, it’s on to a report about ground settlement in the area. One report has reached the conclusion that the drawdown of an aquifer by the “dewatering” for the access pit caused November’s settlement. But that has stabilized, Trepanier goes on to say. “That type of settlement is no longer going to continue,” they believe. In all, he adds, three reports related to the settlement are out – and they don’t all agree with each other regarding other points. One specific area, he adds, is believed to be an area “where there’s always been a problem” predating the dewatering.
11:03 AM: Trepanier is showing charts with details of which engineering firm says what. This part of the briefing has lasted much longer than the one about the specific damage has been found in the tunnel machine. After a few minutes of details, he recaps that they disagree with the city over what’s to blame for the Pioneer Square water main that needs to be replaced – “it’s always been a problem” in their view, before the tunnel-project dewatering. He also says that they haven’t found noteworthy structural damage in the area. He also says the aquifer related to the dewatering should eventually have a “rebound effect … when the pump shutoff takes place.”
11:21 AM: WSDOT moves on to an update on what other work is being done while the tunnel machine is being fixed. On this side, the South Operations Building is taking shape, he notes. And WSDOT is writing its response to the city’s evaluation of the Viaduct, Trepanier adds.
11:29 AM: Briefing is over. We’re taking down the live-video window; we’re expecting the slide deck from WSDOT in a bit and will add that when it’s available.
11:43 AM: WSDOT has published its own summary, here.
12:11 PM: And now we’ve received the slide deck, and added it atop this story.
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