This is the third in a series of three papers discussing significant modifications expected to be included in the 2000 NEHRP Provisions, dealing with the design of precast, prestressed concrete seismic-force-resisting systems. The first article presented an historical review of the development of the NEHRP Provisions while the second article discussed the proposed revisions for seismic-force-resisting frame and structural wall systems composed of precast and prestressed components. This article provides an overview of design issues concerning untopped diaphragms composed of both double-tee and hollow-core slab units.
