Seismic design of steel buildings: lessons from the 1995 Hyogo-ken Nanbu earthquake

Past and current seismic design provisions for steel structures in Japan are presented and compared with Canadian requirements. The performance of steel framed structures during the January 17, 1995, Hyogo-ken Nanbu earthquake is described. Numerous failures and examples of inadequate behaviour could be observed in buildings of various ages, sizes, and heights, and braced with different structural systems. In moment resisting frames, the damage included failures of beams, columns, beam-to-column connections, and column bases. Fracture of bracing members or their connections was found in concentrically braced frames. The adequacy of the current Canadian seismic design provisions is examined in view of the observations made. Key words: earthquake, seismic design, steel structures.