Editor's note: The Pioneer Square Preservation Board postponed its planned discussion and comment on the Alaskan Way viaduct replacement project today (Jan. 19), pending more detailed information from the Washington State Department of Transportation. This story has additional updates, in italics below.
The Polson Building and the 619 Western arts building in Pioneer Square are nearly identical. Both were built as warehouses about 100 years ago, set atop timber pilings made of cedar or fir. Both have structural walls made of reinforced, poured concrete and were framed with more heavy timbers. The two buildings share a common wall, but, it appears, two very different fates.
Reinforced with steel framing about 15 years ago, the Polson Building got a new lease on life as office space to some technology and architectural companies and very well could still be standing 100 years from now. The 619 Western building could face demolition next year. The Washington State Department of Transportation (DOT) has recommended that the building, which serves as studios and gallery space for almost 100 local artists, be torn down in preparation for the state’s plan to replace the Alaskan Way Viaduct with a tunnel.
The meaningful difference between the two buildings, which aesthetically look very much the same, is not the steel framing. The real difference is seemingly small but has proved to be profound: The Polson Building has a basement; 619 Western does not.
According to DOT engineers, that means the pilings of the Polson Building are embedded deeper into the soil, fully beneath the water table which varies by as much as 3 feet with the tide and rises to within a few meters of the surface. The pilings of 619 Western are right at that tidal line. Sometimes they are fully submerged, and sometimes the tops of those pilings are above the water table. Over, the decades, the wet and dry cycles have cause the pilings to rot. The pilings of the Polson Building, completely submerged in water and encased in sediment, are sound due to a unique loophole in the relationship between water and wood.
When exposed to water and air, without the protection of paint or preservatives, wood generally rots. But when wood is completely submerged and entombed, with no light or oxygen, it cures and retains its integrity. The pilings of the Polson Building are like the cut logs submerged in river beds for centuries that are pulled up by lumber salvage companies in as good a condition as the day they were cut down.
As a result, the lines of the Polson Building are square and true, while 619 Western sags and dips as if it were melting slowly into the earth, because in a sense it is. Engineers representing the DOT explained yesterday during a tour of the building that 619 Western is unstable and is “not able to withstand more settlement,” said Rick Conte, an engineer with the firm Parsons Brinckerhoff, contracted by the DOT.
Conte and the DOT’s Ron Paananen, in charge of the viaduct project, said yesterday that 619 Western is unique among the 169 buildings the DOT assessed in preparation for the tunnel project. A handful of other buildings, like the old Federal Building, will be potentially impacted by the construction of the tunnel but do not need to be torn down, they said.
Conte indicated all of the at-risk buildings, except 619 Western, can be saved using a technique called compensation grouting, in which a type of concrete is injected into the soil beneath the buildings, filling any voids and giving the buildings a firmer base on which to sit. The process is proven and was used to shore up and protect Big Ben in London, Conte said, but works only if the building’s foundation is sound. The art building’s foundation is not. Correcting the damage done by the rotting pilings, Paananen said, would cost $30 million, and is not a prudent expenditure of taxpayer money. The cost to demolish the building would be $2.5 million.
During yesterday’s tour, Conte and Paananen pointed out several vertical cracks on the south, exterior wall of 619 Western and on the building’s center, interior wall (also a load-bearing wall). The cracks ran deep and in some cases went completely through the wall.
In general, Conte said, the center of the building is collapsing and the east wall, the side facing Western Avenue, is leaning away from the center of the building. Further settling could damage the Polson Building because the two structures share a wall, with the weaker sibling essentially dragging down the stronger one.
“It is in a very severe condition,” he said, although he could not say exactly what would happen to 619 Western if the tunnel boring did not take place.
To shore it up, engineers would have to rip out the existing slab floor, drive new, steel pilings even deeper into the earth, perhaps 50 to 60 feet, and pour a new concrete slab, all while bracing the building.
Because 619 Western is within the Pioneer Square historic district, its demolition must first be approved by the neighborhood’s preservation board, which meets this morning (Wednesday, Jan. 19) to discuss the issue. The DOT has pledged to assist 619’s tenants by helping pay relocation expenses, although it is not clear how much each artist will receive. The DOT was set to meet with tenants Tuesday night (Jan. 18).
One of the tenants, Johnny O’Brady, said the figures the DOT has thrown out have ranged from $2,000 to $50,000 per tenant, depending on the size of the studio and the corresponding business. He said he is concerned many will be left out because most of the artists do not have business licenses, tax returns, or other documents the DOT has asked for.
“Everyone’s pretty confused about it,” O’Brady said.
The DOT said it will compensate tenants for the cost of moving and for any increase in rent incurred as a result of moving; it will not compensate tenants for any lost time or business. While the upper limit, by law (the Uniform Relocation Act), is $50,000, compensation is expected to vary depending on what needs and expenses each tenant can document.