Seismic response of single-storey buildings with flexible diaphragms

Abstract

The roof framing in single-storey buildings with large foot prints, generally used for commercial, educational, or institutional purposes, often consists of a flexible steel deck or wood panel diaphragm. Resistance to seismic lateral loads is provided by steel bracings, masonry shear walls, concrete shear walls, wood panel shear walls, or cold formed wall systems. The response of such buildings to seismic loads is strongly affected by the flexibility of the roof diaphragm. Diaphragm flexibility alters the manner in which the inertia forces, shears, and bending moments are distributed along the length of the diaphragm. In addition, it causes a significant increase in the ductility demand on the lateral load resisting system that is expected to be strained into the inelastic range under the design earthquake. Results of a study on the linear and nonlinear seismic response of buildings with flexible diaphragms are presented.