KENT – Sound Transit revealed on Thursday that light rail service to the Eastside, which was due to start in July 2023, will open a year or more later as contractors need to reinforce or rebuild 4 miles of concrete track supports defective through Mercer Island and Seattle.
Meanwhile, a landslide in Kent last month revealed the ground to be more unstable than expected, so builders are having to design different underground column foundations. This could delay trains between Angle Lake and Federal Way from late 2024 until 2025.
And on the Northgate-Lynnwood extension, Deputy Managing Director Kimberly Farley expects a four-to-six-month delay beyond the July 2024 target, mainly due to last winter’s four-month strike by drivers of concrete mixer.
The strike is also pushing Redmond’s $1.5 billion expansion, to add Marymoor Village and downtown Redmond stations, to a four to five month delay, past the December 2024 target.
Farley delivered the sobering news Thursday to the Transit Board’s System Expansion Committee.
The main loss so far has been time, for people hungry for efficient train travel and for taxpayers who have been paying since the 2008 and 2016 elections to fund these lines.
Farley said the issues won’t result in massive cost overruns that exceed project budgets.
No cost estimate for these issues has been released and a report indicates that negotiations are underway with construction companies. Events beyond Sound Transit’s control, including the concrete strike and COVID-19, would result in longer contract terms, Farley said, in lieu of additional payments.
“We will open these transformative projects, and we will do so as quickly as possible, with our top priority being our passengers’ needs for safety, quality and long-term sustainability,” said interim CEO Brooke Belman.
East side tracks
Sound Transit has previously acknowledged that its $3.7 billion, 14-mile line between the International District/Chinatown station and the Overlake area will miss its grand opening date of July 2023 due to faults in track supports. concrete, where rails are laid over the old Interstate 90 express lane.
But the project team discovered worse conditions as recently as June.
Contractor Kiewit-Hoffman should partially replace the top 6 to 18 inches of these concrete blocks, known as baseboards, or surround them with reinforcing materials, said Jon Lebo, executive director of the Sound Transit project for East Link. . Contractors and consulting engineers will test different methods, he said.
Problems were first discovered in 2019 and Sound Transit approved the use of mortar to adjust the baseboards, which failed. Workers raised rails this year, grinding and resurfacing poorly constructed baseboards that were the wrong size or contained weak concrete.
“We thought we had a solution to the problem that we were confident would work… Unfortunately, the solutions we implemented failed, and each time we implemented a new solution, we found more problems,” Farley said. Digging deeper, officials discovered too much or too little rebar near the surfaces.
Troubled areas total 4 miles and 5,455 baseboards, Lebo said.
Another type of track support, on the deck of the I-90 pontoon bridge, was structurally sound, but about 1% of the custom nylon inserts were stripped after the metal track clips were bolted on. All 19,400 bolt inserts are replaced and reinforced with epoxy.
Farley said that thankfully, “our relationship with the contractor is quite good. We’re in solution mode, figuring out how to fix these problems rather than pointing fingers at each other.
The Agency’s latest progress report, dated June 30, cited errors and delays blamed on other contractors on several segments of the Eastside line. These challenges range from inadequate bearing pads under raised seating beams to lack of clearance for trains on a curve inside Bellevue’s downtown station to a partial reconstruction of the parking lot at Redmond Technology Station. , where some concrete beams were not strong enough.
Repairs have been completed or may be completed before the I-90 issue is resolved.
Liquefaction near Federal Way
A small shelf of crumbling earth in Kent, about 200 feet long and 9 feet high, caused a three-day closure of a southern lane of Interstate 5 in mid-July, to stabilize the area near South 259th Place, where Sound Transit will construct a guideway antenna.
It was the tip of the iceberg.
Sound Transit says contractor Kiewit-Hoffman now needs to design special foundations, so the track columns will support the girders and trains despite the liquefiable soil.
Columns are typically 50 feet deep, while unstable ground is 0 to 40 feet deep, spokesman David Jackson said. Thus, the modified columns must mainly resist lateral forces in the event of an earthquake.
The site was quiet Thursday morning, with no crew in the troubled area marked by plastic sheeting and a partial retaining wall, as construction continued further south.
Farley said other challenges await the $2.5 billion project, such as constructing and controlling traffic access roads, primarily at Federal Way Downtown Station.
Concrete and rocks
Contractors poured the wrong kind of small rock to ballast the tracks at North Seattle, between Northgate Station and the approach to the future Northeast 130th Station. But they quickly replaced the higher quality equipment this summer, to avoid triggering delays, spokesman John Gallagher said.
A bigger issue was the four-month-long concrete drivers’ strike that halted some crucial pours and prompted layoffs at Northgate’s 8.5-mile, $2.7 billion project in Lynnwood, officials said.
The 1,670-space car park at Lynnwood City Center station was hit by the strike. Farley said train service can begin before the garages are completed, if necessary.
Project reports point to broader, industry-wide problems of too few skilled workers, engineers and mega-project supervisors. This is a potential barrier to some quality control steps that Farley outlines, such as more inspections.
In a staff noteSound Transit accepted the blame for not auditing quality assurance and quality control of subcontractors rigorously enough to catch problems earlier.
A June progress report also mentions the risk that there will not be enough operations experts capable of carrying out months of train testing when the tracks are completed, which could happen simultaneously on two lines or more, and “blind spots” where problems do not occur. being discovered because technical staff familiar with the project are moving on to other jobs, according to reports.
Delays on the Eastside could mean the Bellevue and Redmond runways open at or around the same time, but Farley said it was too early to tell.
And if the Bellevue line – which includes a new train maintenance base – takes longer to complete than the Lynnwood or Federal Way segments, it would foul the overall car supply, and possibly train frequency or length. in the metropolitan area. Farley said staff are already thinking about strategies and will know more later this year when they release new goals for opening dates.
Committee chair Claudia Balducci of Bellevue, who has worked for 15 years to provide Eastside rail, suggested that if I-90 is not serviceable in time, Sound Transit should either bolster its Route 550 express bus to across Lake Washington at a railroad grade. , or even operate a light rail segment reaching only Eastside stations. (Former Redmond Mayor John Marchione mentioned this notion years ago, in case the unprecedented pontoon bridge route was unbuildable.)
Belman pointed out that East Link is the region’s most complex transit project to date.
“This is truly historic. No other region in our country has so much mass transit infrastructure under construction and gearing up to go into service in such a short time,” his memo reads.