A Wall System that Inherently Satisfies Proposed NEHRP Seismic Design Provisions for Architectural Glass

Abstract

Proposed Year 2000 revisions to the 1997 NEHRP Recommended Provisions for the Seismic Regulations for New Buildings and Other Structures (FEMA 302) include first-generation seismic design provisions written specifically for architectural glass components. Scheduled for publication by the Federal Emergency Management Agency (FEMA) as FEMA 368 in 2001, the 2000 updates of the NEHRP Provisions will elevate the degree of design attention paid to seismic life safety issues associated with architectural glass components in exterior building wall systems. In an independent effort, an “Earthquake-Isolated Curtain Wall System” (EICWS) has been developed and tested in the Building Envelope Research Laboratory at Penn State University. By decoupling each story level of the wall system from adjacent story levels, the EICWS has shown an inherent ability to accommodate large interstory displacements in the vertical, horizontal and out-of-plane directions without jeopardizing life safety or compromising wall system serviceability. Thus, the EICWS has demonstrated an inherent ability to satisfy and exceed, by a wide margin, the proposed seismic design provisions for architectural glass that are now being considered for adoption in the 2000 NEHRP Provisions. This paper will include a description of the newly proposed NEHRP Provisions for architectural glass and a summary of recent laboratory tests of the Earthquake-Isolated Curtain Wall System.