The following two project profiles, from our March digital edition, feature some of the best practices in the industry regarding seismic retrofits.
TEAM: Architect: TRO Jung|Brannen Inc., Memphis, Tenn., www.trojungbrannen.com // General contractor: Carothers Construction Inc., Oxford, Miss., www.carothersconstruction.com // Metal-panel installer: F.L. Crane & Sons, Fulton, Miss., www.flcrane.com // Metal wall-panel manufacturer: CENTRIA, Moon Township, Pa., www.centria.com PRODUCTS: Formawall Dimension Series 2 inch; square feet: 73,527; Color: off white; Finish: embossed; Coating: Duracast; Gauge: 22; Cradle-to-Cradle Certified Silver // Formawall Dimension Series 3 inch; square feet: 3,097; Color: surrey beige; Finish: embossed; Coating: Duracast; Gauge: 22; Cradle-to-Cradle Certified Silver // Versawall ; square feet: 10,263; Color: off white and bone white; Finish: embossed striated; Coating: fluorofinish; Gauge: 22; Cradle-to-Cradle Certified Silver // Formavue Windows FV500
Buildings in the Memphis, Tenn., area are situated in an area known to geologists as the New Madrid Seismic Area, one of the largest fault lines in the U.S. After years of study and analysis, the U.S. Department of Veterans Affairs decided the best solution for its Memphis medical center was to retrofit the 30-year-old bed tower to comply with seismic standards set by the state of California, mitigating risks from earthquakes, hurricanes and other natural disasters. By removing the top 11 floors and reinforcing structural concrete walls on the remaining four floors, engineers were able to seismically correct the building. The challenge then became making the structure fit aesthetically with the rest of the campus, having it perform in a consistent, high-quality manner over time and doing it all with an eye toward sustainability. CENTRIA foam-insulated metal panels were specified because of their ability to withstand racking — an effect most large buildings are exposed to, certainly during an earthquake — because of its attachment to the substructure at only one side. The lightweight panels were affixed to the existing structure with only minor additional structural support. With only one lightweight system to install, wall construction is more efficient and cost-effective. The building’s exterior had to achieve a cohesive campus look and correlate with the remainder of the existing pre-cast building. Using CENTRIA’s Duracast textured finish, the building team was able to mirror the existing pre-cast concrete building design. Formavue window systems — designed to integrate with Formawall Dimension Series — correlated visually with the overall project and offer a standard thermal break to provide weather resistance. Finally, Versawall panels offered an excellent design solution for the penthouse enclosures.
TEAM: Project owner: Walden House Inc., San Francisco, www.waldenhouse.org // Project funding: Mayors Office of Housing, San Francisco, www.sfgov.org/moh // Seismic retrofit contractor: West Coast Premier Construction Inc., Oakland, Calif., www.wcpc-inc.com // Construction manager: Swinerton Management & Consulting Inc., San Francisco, www.swinerton.com // Project engineer: Structural Design Engineers Inc., San Francisco, www.sdesf.com // Project architects: Cee Architects Inc., San Francisco, www.ceearchitects.com
The adult residential facility is part of a nonprofit organization providing substance abuse and mental health-related services. The historic four story landmark building was constructed of non-reinforced brick masonry, which was a safety concern in the case of a seismic event. The seismic retrofit consisted of the following:
- Removal of the existing roof
- Adding roof diaphragm strengthening
- Re-roofing approximately 8,400 square feet
- Installation of new shotcrete, concrete masonry blocks and wood-framed shear walls as new lateral seismic resisting systems
- Installation of steel moment frames with new foundations
- Installation of new wall-to-floor steel anchors and hardware at each floor
- Installation of new parapet braces and collector (tie) hardware throughout the building