Eccentric braced frames: A new approach in steel and concrete

The current practice of seismic design in different parts of the world and the performance of buildings in an earthquake have revealed the inherent limitations of earthquake resistant design.; Two structural systems proposed in this thesis address these limitations in a new way: (a) Concrete Eccentric Braced Frame. Here the sudden brittle failure of a concrete infill frame is avoided and made ductile by introducing a fuse in the form of link beam (eccentricity). However the damage (inelasticity) is confined and restricted to infill (masonry) only. These infills can be replaced after the earthquake. And it is also shown that staggering the infill wall controls the pattern of damage. (b) Variable Eccentric Braced Frame. This is essentially an eccentric braced frame but damages (inelastic behavior) in an earthquake is restricted to bracing as against the conventional eccentric frame where the damages occur at the link beam. These braces can be replaced after the earthquake. Variation of eccentricity is used to control the pattern of failure.