Seismic Design of Single-Story Buildings With a Nonlinear Flexible Roof Diaphragm


Abstract eng:
Single-story buildings with large footprints form a significant portion of the inventory of industrial buildings in North America. Such buildings are designed to serve a variety of functions, including recreational, commercial, educational and industrial. Steel decks or wooden deck panels, which exhibit low in-plane stiffness, often form the roofing system for these buildings. Previous studies have shown that the flexibility of the diaphragm significantly affects the seismic response of single-story buildings. A roofing system with low in-plane stiffness lengthens the period of the structure, increases the ductility demand on the seismic force resisting system, and alters the distribution of the earthquake-induced inertia forces along the length of the diaphragm. Change in the distribution of inertia forces leads to an increase in the internal forces in the diaphragm. Specifically, the shear force at quarter-span and bending moment at mid-span both undergo significant magnifications. The common approach to the design of single-story buildings with flexible diaphragms is to ensure that the roofing system remains elastic, while the seismic force resisting system is allowed to deform into the nonlinear range to dissipate the seismic energy imposed on the system. Although this approach is widely practiced as the design strategy for such systems, it often leads to uneconomical designs. Recent experimental studies have shown that steel deck panels have fair capacity for energy dissipation through inelastic cyclic deformations. A design in which the diaphragm is allowed to become inelastic would therefore be acceptable, provided the ductility demand is limited. In fact, several building codes now allow a limited amount of inelastic deformation in the diaphragm. However, related information on the design is lacking. For instance, the relationship between the ductility related force modification factor and the target ductility has not been established. This paper reviews the findings of previous studies on the seismic behavior of single-story buildings with flexible diaphragms and presents the results of an analytical study to examine the structural implications associated with a design that relies on the roofing system to act as the energy dissipation system. A set of buildings is selected and designed using several alternative energy dissipation mechanisms. The selected buildings are subjected to a number of spectrum compatible records and the response results are used to develop empirical expressions for determining the key design parameters. Procedures are then developed for the design of single-story buildings including buildings in which the flexible steel deck diaphragm is expected to undergo inelastic deformations.

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Conference Title:
Conference Title:
16th World Conference on Earthquake Engineering
Conference Venue:
Santiago (CL)
Conference Dates:
2017-01-09 / 2017-01-13
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Text je chráněný podle autorského zákona č. 121/2000 Sb.



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 Record created 2017-01-18, last modified 2017-01-18


Original version of the author's contribution as presented on USB, paper 3753.:
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