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Aydınoğlu M. N. , Polat Ş., Beyen K.

US - JAPAN WORKSHOP ON SOIL-STRUCTURE INTERACTION, California, United States Of America, 22 - 23 September 1998, vol.1, pp.1-17

  • Publication Type: Conference Paper / Full Text
  • Volume: 1
  • City: California
  • Country: United States Of America
  • Page Numbers: pp.1-17


The idea behind the present paper has originated from the observation of the
extensive use of the so-called tunnel formwork system in Turkey during the last
decade for the mass-construction of multi-storey residential buildings. Such buildings
are made of merely reinforced concrete walls and slabs resulting in extremely stiff
structural systems. When they are supported through raft foundations on relatively
soft soils, almost ideal conditions are created for the pronounced effects of seismic
soil-structure interaction. Contrary to the traditional engineering approach and the established seismic code
procedure of soil-structure interaction analysis based on the appropriate modification
of fundamental period and the effective damping of the structure (BSSC 1995), the
present study attempts for the determination of a fictitious equivalent input ground
motion to be applied to the fixed-base structure system in its fundamental mode
without necessarily modifying its dynamic properties. Thus, this alternate approach
makes it possible to develop modified response spectra applicable to the first mode
response of soil-structure systems. Although such output requires the full analysis of
SSI systems, it may be justified if the systems under consideration can be
standardised, as in the case of above mentioned uniform shear wall building structures
which may be characterised by few independent parameters only.
The present paper does not have any claim in terms of originality of research
except that SSI effects are demonstrated in a different fashion. It is anticipated that
practical engineers who, in part, still experience some difficulty in understanding the
favourable and/or unfavourable effects of soil-structure interaction, may find it more
interesting to observe how SSI affects the building response as it is directly read from
the familiar pseudo-acceleration response spectra.