Soil-structure interaction in seismic analysis

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.

Alexander G.Tyapin (b.1957) graduated from the Moscow Power Engineering Institute (1980) and worked with Professor V.V.Bolotin until 1992. Since 1992 A.G.Tyapin has been working with JSC "Atomenergoproject". Doctor of Science (1995). Specialist in Soil-Structure Interaction, published over 250 papers in Russian and English and four books in Russian, which were awarded a Medal of the Architecture and Civil Engineering Academy of Russia (2019). Carried out design SSI analyses for Nuclear Power Plants in Russia, Iran, Bangladesh, Bulgaria, Turkey and India.