Akademik Veri Yönetim Sistemi
6th International Congress of Earthquake Engineering and Seismology, Kocaeli, Türkiye, 13 - 15 Ekim 2021, cilt.1, sa.1, ss.430-441
In our country for
residential, car park and business purposes, in order to be able to use the
buildings the basement and ground floors of the buildings as open. The use of
basement and ground floors for this purpose causes the soft floor effect to
occur. In this study, a total of eight four-story steel structures with or
without isolation formed by central or eccentric braced are considered. The
ground floor of these structures is not formed with central or eccentric steel
braced and is designed as a soft floor. Excessive shear force, bending moment
and lateral displacement are expected in the columns of the floors that have
soft story effect during the earthquake of the investigated structures. In soft
floor columns, two types of passive isolation systems are used, namely the
friction pendulum isolation system or the lead-based rubber system passive base
isolation system, in order to reduce these effects and to use these floors for
parking or workplace purposes. In this study, isolation systems were placed
between the foundation and the structure to transmit seismic effects to the
building during an earthquake and to increase the natural dominant period of
the building. Firstly, non-linear analysis in the time domain of non-isolation
structures with soft-fold effect was performed. Later, nonlinear analyzes in
the time domain of the structures with floor insulated soft story effects were
made. A series of results was obtained by comparing the analyzes made.
According to the analysis results, it has been observed that both isolation
systems reduce the shear forces, lateral displacements and bending moments
occurring in the columns of the floor that has a soft floor effect. However, it
has been achieved that in the friction pendulum isolation system, it can absorb
the energy from the earthquake more than the lead-based rubber system isolation
system. In the steel structure formed as an eccentric braced, the soft floor
effect is less prominent than the steel structure formed as a central braced. Since
the tie beams formed by the eccentric steel braces can meet the earthquake
effects, it has been proposed to create a steel structure system with an
eccentric braced in structures with soft story effect. In addition, the use of
passive insulation systems and cross members together will limit the possible
soft story effect on the steel structure.