Bracing Hewlett-Packard's Corvallis building
Seismic upgrades for high-tech manufacturing behemoth Hewlett-Packard Co.'s Corvallis, Ore., campus presented a different type of retrofit challenge: to strengthen a 26-year-old light industrial facility with minimal visual impact and without disturbing its integrated-circuit and inkjet pen manufacturing operations.
Hewlett-Packard assembled a building team that included Degenkolb Engineers, IDC Architects and Andersen Construction Co., all with Portland, Ore., offices. The 19-month project was completed last November.
The 225,000-sq.-ft., two-story project features an $18.6 million external bracing system on the building's existing column lines. The system consists of nine braced frames in the building's transverse direction on the north and south walls and five brace bays on each longitudinal exterior column line. The frames maintain the original roofline and occupy exterior space originally taken by sunshades that extended 14 feet out from the building.
"For the frames to work effectively, they were tied together at the roof level across the building's 200-ft. width with tube-steel members at each of the nine frame lines," explains Brad Nile, project manager with Andersen Construction. "The tubes were installed in segments by removing the roofing and insulation and attaching them to the existing metal roof deck. The tie at the roof level provides a dual function: it forces the frames on the opposite side to move together during an earthquake, and it acts as a collector to deliver seismic load from the roof level to the new frames."
The braces were fabricated off site and then assembled and erected on site, allowing all nine frames on each side of the building to be installed in a day. Demolition was performed alternately on the north and south sides so as to not disrupt everyday operations. Moreover, a temporary weather barrier extending 4 feet into the office space and covered walkways between buildings helped to maintain campus circulation displaced by construction.