Bankia binge on Pier

by Lucy Bodilly

Animal lovers will be able to visit two new attractions soon, one at Woodland Park Zoo and the other at the Seattle Aquarium.

It's amazing what damage a mollusk can do.

Tiny shelled creatures called bankia, prevalent in Puget Sound, are forcing contractors to replace part of Pier 59, the foundation for the Seattle Aquarium.

Bankia, a type of mollusk, are the best friend of marine contractors everywhere, but in this case, they're helping the aquarium, too. The pier repair is allowing an expansion at the aquarium.

Overall the project cost is $20 million.

Located at Piers 59 and 60 on the Seattle waterfront, the 20,000-sq.-ft. expansion of the aquarium includes a new entry lobby, ticket office, café, gift shop and a double-height Great Hall for daytime exhibits and evening events. The new space will have natural ventilation, daylight harvesting and a raised access floor for future program flexibility.

The project also includes a new 140,000-gallon, two-story exhibit called "Window on Washington Waters," designed by BIOS LLC, which will highlight native aquatic species from the Northwest coast.

Architect for the exterior of the building, owned by the Seattle Parks Department, was Miller Hull of Seattle. Mithun, also of Seattle, designed the interior under contract to the Seattle Aquarium Society.

Bankia are only several centimeters in length, but they're voracious. The larvae enter pinholes in wooden piles at ground level and eventually eat their way down to about 2 ft. below the sand. They leave behind large tunnels in the piles, weakening the structure.

advertisement

Replacing the piles was the most technically difficult part of the project, according to Tim Charoni, project manager with Turner Construction of Seattle.

The project's structural engineer, Seattle Structural, devised a plan to remove 270 wooden piles and replace them with steel ones and a channel and pilecap system that would greatly improve the structural integrity of the pier.

But first, crews from ACC/Hurlen, a marine contractor in Seattle, and J.P. Francis, a Seattle, had to jack up the pier and inspect each pile for bankia damage. The base of the piles that were still sound could be used to support the new steel pile.

Badly damaged piles had to be removed below the mudline, allowing a new steel pile to be placed over the wood structure. Divers had to do the work.

Turner is known for its commercial construction work, and even though this project is primarily a marine job, Charoni said the firm was chosen for its project management skills.

Upcoming projects such as the overhaul of the Coleman dock ferry terminal in Seattle are also expected to go to contractors with heavy project management skills.

Another part of the project called for relocating utilities under the pier and relocating the pump house that feeds the aquarium tanks. The HVAC room and air-handling equipment were also relocated to the west side of the pier.

Shell work for the aquarium addition will start in June, after the pier is reconstructed.

"Because the building is a historical landmark, it will look pretty similar to the way it is now," said Julie Montgomery, project architect with Miller Hull.

Zoo Building Caters to the Human Animal