A Damage‐Controlled Behavior Factor (EC8) for Seismic Design of Steel Irregular Space MRFs

Abstract

AbstractA main aspect to consider in seismic design of building structures according to EC8 is the selection of the behavior factor, q, which is directly related to the energy dissipation capacity of the structure. The prescribed values of q (1) are referred only to one limit state; (2) depend on the structural system and on the ductility class; (3) are constant; and (4) are not directly related to structural and non‐structural demands. Based on the literature, the inelastic seismic response of irregular building structures cannot be always estimated with safety by utilizing the methods of current seismic design codes. In this work, a preliminary performance‐based seismic design method which incorporates deformation‐controlled q factors, to better control the structural and non‐structural damage, is developed for space steel moment resisting frames irregular in plan view and in elevation within the framework of hybrid force/displacement (HFD) seismic design method. A large seismic response databank is generated on the basis of 88 space irregular MRFs, subjected to 42 pairs of ordinary ground motions, to develop the necessary empirical equations employed by the HFD. A realistic design example serves to demonstrate the advantages of the proposed method over the seismic design procedure of EC8.