Soil-structure interaction (SSI) is an important phenomenon in the
seismic response analysis. As seismologists describe seismic excitation
in terms of the seismic motion of certain control point at the free
surface of the initial site, the question is whether the same point of
the structure (after structure appears) will have the same seismic
response motion in case of the same seismic event.If yes, then seismic
motion from seismologists is directly applied to the base of the
structure (it is called ''fixed-base analysis''), and they say that ''no
SSI occurs'' (though literally speaking soil is forcing structure to
move, so interaction is always present). This is a conventional approach
in the field of civil engineering. However, if heavy and rigid structure
(sometimes embedded) is erected on medium or soft soil site, this
structure changes the seismic response motion of the soil as compared to
the initial free-field picture.Such a situation is typical for Nuclear
Power Plants (NPPs), deeply embedded structures, etc. The book describes
different approaches to SSI analysis and different SSI effects. Special
attention is paid to the Combined Asymptotic Method (CAM) developed by
the author and used for the design of NPPs in seismic regions. Nowadays,
some civil structures have parameters comparable to those of NPPs (e.g.,
masses and embedment), so these approaches become useful for the civil
structural engineers as well.
