SEISMIC DESIGN OF SECONDARY STRUCTURES - STATE-OF-THE-ART

The developments in the last three decades in the area of seismic desi gn of mechanical and electrical equipment, architectural components, a s well as other secondary structures and nonstructural components atta ched to the floors, roof, and walls of buildings are reviewed here. A description is made of what constitutes a secondary structure, the cha racteristics that make these systems particularly susceptible to the e ffects of earthquakes, and the parameters that affect their response t o earthquakes. The methods that have been proposed and are available t o improve and simplify the analysis of this type of structure, the met hods that are currently used as reflected by various building codes an d seismic provisions, and the experimental studies and field observati ons carried out to further investigate some of their dynamic propertie s and response characteristics are also reviewed here. The paper close s with a summary of what research is still needed to advance current e fforts to protect these systems against the effects of earthquakes and to develop methods and techniques to achieve this goal in a practical and economical way.