Eng. Dan Iancu, Eng. Ştefan Marin
Modern design trends of structures aim to protect the
facades, finishing, equipment integrated in buildings as well as reducing
plastic deformations (remanent). These objectives come from operational considerations of
the building following a seismic event, protection of the investment of
which a significant percentage results from building façade and partitions, finishes and technical and technological equipment of
the building, as well as reducing the commissioning costs after a seismic event.
Transposing these issues into design requirements necessitates, in the case of the conventional structure design approach,
considerations of low behavior factor in order to
minimize the level of degradation of the respective structure
and to minimize the plastic deformations in the structural elements. The deformations of the structural elements are transposed into
deformations of all the systems connected to the structural system.
The alternative involves the consideration of a base isolation system of the building which effectively solves
the aforementioned desideratum, but which involves a calibration of the solution with nonlinear dynamic analyses
using real and/or synthetic accelerograms.
It is thus up to the structural engineer to choose the sets of artificial accelerograms
generated from the design response spectrum or scaled for compatibility with the design
The purpose of the article is to present some methods of scaling of natural records,
the variation of the maximum displacement of the base isolation system for a structure with low-height regime
and a high-rise structure, design aspects of the
base isolation systems for the two studied structures, remanent displacements of
the base isolation systems and selecting the number of accelerograms to determine the movement of the
base isolation system.