More delays for light rail to Bellevue, Redmond, Federal Way, Lynnwood

By Mike Lindblom, The Seattle Times

KENT — Sound Transit revealed Thursday that light-rail service to the Eastside, which was to begin by July 2023, will open more than a year later because contractors must reinforce or rebuild 4 miles of flawed concrete track supports through Mercer Island and Seattle.

Meanwhile, unstable soil in Kent is worse than expected, so builders must design different underground column foundations. That could delay the line from Angle Lake to Federal Way from late 2024 until sometime in 2025.

And on the Northgate-Lynnwood extension, Deputy CEO Kimberly Farley anticipates a holdup of four to six months beyond the July 2024 target, mainly because of last winter's four-month strike by concrete-truck drivers.

The strike is also pushing the Redmond extension, to add Marymoor Village and downtown Redmond stations, toward a four- to five-month delay, after the December 2024 goal.

Farley delivered the frustrating news Thursday to the transit governing board's System Expansion Committee.

So far, the main thing lost is time, for travelers eager for efficient train travel and for taxpayers who've been paying since the 2008 and 2016 elections to fund these lines.

Farley said the problems won't result in massive cost overruns that would exceed project budgets.

No cost estimates related to these problems were released, and a report said negotiations are still underway with construction companies. In general, events beyond Sound Transit's control, including the concrete strike and COVID-19, would lead to longer contract deadlines, instead of extra payments, Farley said.

"It's going to be just fine," she said in an interview. "There are issues in all megaprojects. You have issues you must overcome, and we will overcome every one of these issues."

Eastside trackways

Sound Transit previously acknowledged the 14-mile line from International District/Chinatown Station to the Overlake area would miss its June 2023 grand opening date because of flaws in concrete track supports, where rails are being laid over the former I-90 express lanes.

But the project team discovered worse conditions as recently as June.

Contractor Kiewit-Hoffman is expected to partially replace the top 6 to 18 inches of these concrete blocks, known as plinths, or to surround them with reinforcing materials, said Jon Lebo, Sound Transit's executive project director for East Link. Contractors and advising engineers will conduct tests of different approaches, he said.

Workers have been lifting rails this year, to grind and resurface plinths that were built incorrectly to the wrong dimensions or contained weak concrete. A previous attempt to solve those problems with mortar failed. Digging deeper, officials discovered too much or too little rebar near surfaces, Lebo said.

The troubled areas total 4 miles and 5,455 plinths, he said.

Other track supports, on the I-90 floating bridge deck, are generally sound, but some nylon inserts became stripped after metal rail fasteners were bolted in. All 19,400 bolt inserts are being replaced and strengthened by epoxy.

Farley said that, fortunately, "our relationship with the contractor is quite good. We're in solution mode, to find out how to resolve these issues rather than point fingers at each other."

The most recent Agency Progress Report, as of June 30, mentioned several less time-consuming problems that delay most heavy construction contracts on the Eastside. These range from bearing pads under elevated track girders to a lack of train clearance at a curve inside Bellevue Downtown Station to a partial rebuild of the Redmond Technology Station parking garage, where some concrete beams weren't strong enough.

Repairs are either completed or likely to be done before the I-90 problem is solved.

Liquefaction near Federal Way

A small shelf of crumbling dirt in Kent, about 200 feet long and 9 feet high, caused a three-day closure of a southbound I-5 lane in mid-July, so workers could stabilize the area near South 259th Place.

Sound Transit says contractor Kiewit now needs to engineer special foundations, so that trackway columns will support girders and trains despite the liquefiable soil.

Columns are generally 50 feet deep, while the unstable soil is 0 to 40 feet deep, spokesperson David Jackson said. So the modified columns mainly need to resist lateral force in the event of an earthquake.

The site was quiet Thursday morning, with no crews in the troubled area but plastic sheets and a partial retaining wall, as construction continued farther south.

Farley said some other challenges await, such as how to construct and control traffic access roads, mainly at Federal Way Downtown Station.

Wrong rocks

Contractors poured the wrong kind of small rock to ballast the rails in North Seattle, between Northgate Station and the approach to future Northeast 130th Station. But they rapidly substituted better-grade material this summer, to avoid triggering delays, spokesperson John Gallagher said.

A greater problem is the four-month concrete drivers strike that interrupted some crucial pours and caused layoffs in the 8-mile project from Northgate to Lynnwood, officials said.

The 1,670-space parking garage at Lynnwood City Center Station was affected by the strike. Farley said train service can begin before garages are completed, if need be.

Project reports point to broader problems, throughout the region, of too few skilled trades workers, megaproject engineers and supervisors. That's an obstacle to some quality-control steps Farley described, such as more inspections.

Risks include a lack of operations experts who can conduct train tests when the tracks are finished, which could happen simultaneously on two or more lines, and "blind spots" as white-collar staff move around to other jobs, reports say.

Delays on the Eastside might result in Bellevue and Redmond tracks opening at or near the same time, but Farley said it's too soon to know if that will occur.

In a staff memo, Sound Transit accepted some blame for failing to audit contractors' quality assurance and quality control rigorously enough. "In our reviews, we did not identify the issues. Our program was not robust enough to identity the problems with the contractors' QA/QC program," it says.

But Farley and interim CEO Brooke Belman also emphasized that East Link is the region's most complex transit project to date.

"This is truly historic. No other region of our country has so much transit infrastructure concurrently under construction and preparing to enter service in such a compact timeline," they wrote.

___

(c)2022 The Seattle Times

Visit The Seattle Times at www.seattletimes.com

Distributed by Tribune Content Agency, LLC.

Daily News Briefing