91视频

The team planning a wood-framed skyscraper in the Pearl District is checking off boxes on its way to building one of the country’s first modern timber high-rises. And with the conceptual stage now complete, the impending engineering phase could help the federal government devise a permitting pathway for an emerging building product.

The 12-story Framework tower (not to be confused with the five-story Framework building at 160 N.E. Sixth Ave.) is intended to serve as a West Coast showpiece of cross-laminated timber, a mass-timber product already in use as a structural component in other parts of the world. The Framework team has released additional details as it begins testing the building’s fire, acoustical and seismic resiliency systems.

鈥淭his project is almost like two projects in the sense that it’s a real estate and development project, and then there’s this research and development 鈥� R and D 鈥� effort that supports that real estate project,鈥� said Anyeley Hallova, principal with the project’s developer, project^. 鈥淭he goal of this effort is to have one of the first tall wood buildings in the United States, but also to serve as a catalyst to take us through the permitting process.鈥�

CLT is not that different from other existing mass timber products, such as glued-laminated timber, but its far greater strength has designers envisioning a return to a time when wood dominated the urban skyline.

Initial designs by a team led by architect Thomas Robinson of Lever Architecture won the project $1.5 million in federal funding (the other half of the award went to a team in Manhattan). The U.S. Department of Agriculture held the contest in the hope that the two projects would help blaze a trail for future tall wood buildings by clearing permitting hurdles.

鈥淐urrent code doesn’t allow for a 12-story mass-timber high-rise, so we have to demonstrate with very sophisticated testing of fire, seismic and acoustic systems that we’re meeting the basic requirements that are in the code,鈥� Robinson said.

The project as proposed will be constructed primarily of an innovative beam-to-column CLT structural system, to be tested with assistance from Oregon State University and Portland State University. It’s expected that CLT will be used for the floors and a seismically-secure lateral force resisting system, in conjunction with glulam beams and glulam columns. The super-structure will be supported on a conventional reinforced concrete mat foundation.

The system is unique in that it features a predetermined rocking plane at the base of the wall, replaceable energy-dissipating 鈥渇uses,鈥� special floor-to-wall connections and the self-centering characteristics of the post-tensioning system.

(Earlier this spring, the 91视频 watched OSU researchers test a rocking wall system at the school’s Hinsdale Wave Research Laboratory in Corvallis.)

Fire is still wood’s greatest enemy, but CLT’s proponents say the product is not nearly as dangerous as some might think. With assistance by the Southwest Research Institute in San Antonio, various connections of CLT panels and glulam columns will be burn-tested for two hours. The test is designed to simulate the worst possible fire a building could face, and in the event that the sprinkler system fails.

鈥淭here’s always risk in every test,鈥� Robinson said. 鈥淏ut we are very confident that we will be successful. We’ve done a lot of up-front work, modeling and researching these systems.鈥�

The project team has released additional design information and new renderings. The building’s main entrance has been relocated to a corner of the site to create a more inviting lobby 鈥渨ith a more civic presence.鈥� Mass-timber building elements will be visible from the street and the lobby will feature a mass-timber showcase and small cafe.

The Albina Community Bank branch will be located along the Northeast 10th Street frontage near the Portland Streetcar stop. The building will have a double-height community room at the north street corner.

The aluminum composite material facade will now contain recessed window openings sized for residential and office units.

While minor compared to fire and seismic, acoustical testing is important for the project to achieve 鈥渁ffordable鈥� status.

StructureCraft Builders was added as a consultant to tackle issues related to constructability, value engineering and product sourcing. The project team wants at least 50 percent of the project’s wood to originate in Oregon.

Five floors of offices and five floors of apartments are planned in Framework. The 60 residential units will be available to people earning 60 percent of the area median income.聽Home Forward is a co-developer of the building and will own and operate the affordable units.

Much of the cost savings associated with CLT comes during the construction phase, which can be much shorter than for traditional projects because of the product’s prefab nature. Much of the third construction phase is still up in the air, but general contractor Walsh Construction has been involved at every step so far, Robinson said.

Hallova was careful not to say there is a race on with the Manhattan real estate partnership that also is developing a tall wood building.

鈥淥ne of the things we need to have is supportive jurisdictions, and I think we definitely have that advantage in the state of Oregon,鈥� she said.

Framework

Construction cost: approximately $39 million

Anticipated construction start date: January 2017

Anticipated opening date: February 2018

Developer: project^

Affordable housing developer: Home Forward

Architect: Lever Architecture

Structural engineer: KPFF Consulting Engineers

MEP engineer: PAE Consulting Engineers

Civil engineer: TCC & Associates

Fire and timber engineer: Arup

Mass timber consultant: StructureCraft Builders

Landscape architect: 2.ink Studio

General contractor: Walsh Construction