91视频

One of the tallest projects under way in Portland is rising quickly in downtown, not far from near Tom McCall Waterfront Park.

The 469,000-square-foot 140 Columbia mixed-use tower will have 349 residential units, 236 motor vehicle parking spaces on levels two through five, and more than 14,000 square feet of ground-floor retail space. GBD Architects designed the building for Dallas-based developer Alamo Manhattan, and Andersen Construction is serving as general contractor.

The structure is being built at 140 S.W. Columbia St., adjacent to the KOIN Tower, on a 0.92-acre full block. There will be a five-story full-block podium topped by an L-shaped tower; the north wing of the tower will be 20 stories, while the west wing will be 15 stories.

Rooftop balconies will distinguish the sixth, 15th and 20th levels, with amenity space included at each of these levels. The sixth floor will have a 3,200-square-foot terrace, and the 20th floor will sport a large lounge and community room for residents.

鈥淩ight now they’re working on level 10, on the south half of the deck,鈥� Andersen Construction project engineer Cody Cloe said. 鈥淪o, there’s PT, rebar and in-slab stuff going in; probably most of the activity is up there right now.鈥�
听

Crews are averaging completion of one post-tensioned concrete deck every two weeks. Recently, they set post-tensioned cables, rebar and MEP systems in preparation for slab pours.

On lower levels, Western Partitions Inc. carpenters are framing interior walls and installing drywall, while specialists lift and place facade panels.

Major subcontractors on site these days include: R2M2 Rebar and Stressing, whose ironworkers are laying rebar and post-tensioned cables; Ocean Park Mechanical, whose workers are installing both dry and wet HVAC and plumbing systems; Eastern Steel Erectors, whose ironworkers are erecting structural steel, stairways and other fittings; Patriot Fire Protection, whose sprinkler fitters are installing equipment; and Andersen Structural Inc., whose carpenters are performing structural concrete work.

The building will replace a longtime surface parking lot owned by Downtown Development Group. However, a concrete 鈥渂unker鈥� providing entry from Southwest Clay Street to below-grade parking serving KOIN Tower has been retained. It will be incorporated into the new building, which wraps around the existing structure without relying on it for structural support.

The 140 Columbia exterior facades on Southwest First Avenue and Clay Street will feature a gradient pattern stretching from the tower to the parking structure. The pattern begins with smaller window openings that become larger and more transparent toward the corner of First and Clay. Similar patterns are found on the rest of the building.

Construction of facades on the first five levels is being done with prefabricated wall panels that include everything from metal framing to envelope materials as well as precast concrete facade panels manufactured by Knife River at its Harrisburg plant. The complete wall panels are being trucked to the highly constrained site as needed and lifted into place with a mobile crane and carpenters from Western Partitions Inc.

Brick masonry will be the predominant exterior material on levels six through 20.

鈥淭hey’ve got some precast panels being flown on the north face of the building that actually have waterproofing and everything in the panel,鈥� Cloe said. 鈥淭hese prefabricated wall panels have the finished product on them in most cases.鈥�

Project delivery is scheduled for late 2020.