Balanced Window Systems (Curtain Walls and Glazing)
Development and implementation of less costly and more architect-friendly design guidelines for balanced window systems and blast-resistant curtain walls.
Significant improvements in the ability to analyze glass allowed Weidlinger to create a blast-resistant balanced window system to replace the GSA standard of thick windows with rigid frames. The Weidlinger system, now the industry standard, proved flexible enough to be developed into a blast-resistant curtain wall system. The frame and anchorage capacity were matched to glass capacity to provide the most comprehensive protection. The Weidlinger system was used to design the Las Vegas Federal Courthouse and the new Oklahoma City Federal Building. Field tests on the Las Vegas structure persuaded Weidlinger that the blast energy absorbed by a curtain wall as it deforms permits the use of less costly glass to protect occupants. Based on the success of the firm's design for the Las Vegas Courthouse, Weidlinger received a US government contract to develop Protective Design Guidelines for Curtain Wall Systems. Historically, glass is the greatest hazard to people in or near buildings under attack. Although upgrading the building facade is the single most costly improvement, it offers the greatest level of protection to occupants. In general, the alternative to reducing the size of windows is to improve their post-damage behavior. Glass-hazard mitigation solutions include strengthened glazing, laminated glazing, film applications, blast curtains, and energy-absorbing systems. Glass fragmentation is not the only concern, however. Frames, mullions, and connections must withstand the large forces collected by the glazing, while the walls to which the windows are attached must be strong enough to accept the reaction forces.
Completion Date: 2003 Location: United States Owner or Client: General Services Administration (GSA) Prime Consultant(s): WAI Prime