Two topics of practical significance are discussed : (a) The widely-held perception, reflected in q1/ mp){
most seismic codes, that soil-structure interaction (SSI) plays invariably a beneficial role ( and thus | Y(
can be ignored in design to be on the safe side) is shown to be the result of a misconception ,%y!F3 m
stemming from the shape of current design response acceleration spectra for soft/deep soil iX>)6)uJ
conditions. Properly normalising the structural period by a dominant period of motion before q+lCA#Sx
statistically processing recorded response spectral values, produces completely different shape and h?GE-F
size of spectral ordinates ; thus an increased period due to SSI may lead to higher response. 2k`Q+[?{q>
(b) Analytical, experimental and field evidence in recent years has started revealing that seismic L|A1bxt
design of shallow foundations could overcome the strict limitations of the so-called “capacity K-@cn*6
design”, by allowing significant sliding, uplifting, and even mobilisation of bearing–capacity MLmv+
failure mechanisms to occur. It is shown that under seismic conditions such dynamic inelastic– F @ZB6~T~.
nonlinear response may merely lead to acceptable permanent horizontal and rotational of`WP
deformations.
