Ground Motions and Structures - Earthquake Engineering for Structural Design - page 341

Ground Motions and Structures 341

8.5DEVELOPMENTOFSTEELSTRUCTURALSYSTEMS

8.5.1Main StructuralTypes

In recent times, many new structural systems or devices using non-conventional civil
engineering materials have been developed, either to reduce the earthquake forces
acting on a structure or to absorb a part of the seismic input energy. Due to the bad
behavior of some steel structures during the Northridge and Kobe earthquakes, the main
important developments in structural systems are particularly observed in steel
structures. Figure 8.38 shows four conventional types of techniques employed to
control the structural response during earthquakes through inelastic deformations in
structural members: moment resisting frame, centrically braced frames, eccentrically
braced frame and infilled frames. There are many variations under each broad category
and many new techniques are being developed, evaluated and implemented, as
discussed below.

(a) (b) (c)

(d)
Figure 8. 38 Conventional types of structural systems: (a) Moment resisting frame;
(b) Centrically braced frame; (c) Eccentrically braced frame; (d) Infilled frame
(Mazzolani, 2000a,b)