Developments in seismic structural analysis and design

After a brief overview of the world-wide state-of-practice in seismic
design, nonlinear structural response spectra for strength, ductility
and number of yield reversals as a function of building period and
structure strength for several strong motion earthquakes are presented.
Illustrations of three-dimensional mesh surfaces for the
absolute seismic energy input and the dissipated hysteresis energy
for selected earthquakes are given. These results are compared
with conventionally evaluated elastic response spectra and code
criteria. The issues of overstrength factors in the Mexico City code
are then examined. The remainder of the paper is devoted to the
description of a simple frictional energy dissipating connection. Its
behaviour in cyclic tests and in shake table tests of a three-storey
braced steel structure is illustrated.