Displacement-based seismic design of buildings - theory

The conceptual basis of the spectral acceleration-based design method curre ntly used in seismic codes is reviewed and its limitations are discussed. A n alternative method that uses displacements as the basis for the design pr ocedure is then presented. Its conceptual basis for elastic and inelastic s eismic design and its application to single-degree-of-freedom and multi-deg ree-of-freedom structures are reviewed. The effects of torsion are consider ed. The advantages of this method over the spectral acceleration-based desi gn method are also discussed. To the authors' knowledge, this and the accom panying paper mark the first application of the displacement-based procedur e to the seismic design of (steel) buildings. (C) 1999 Elsevier Science Ltd . All rights reserved.