Optimum design of seismic isolated steel construction buildings with triple friction pendulum bearings

Considering the fact that seismic isolation increases the period of the structures and decreases the floor drifts, it is known that it has a great effect on the earthquake resistance of the structures. However, it should be investigated that isolated buildings can have lighter designs than fixed-base buildings, and thus reduce the design cost of the structure, provided that certain deformations are allowed so that the structures remain within safe limits. The aim of this study is to make optimum weight designs of seismic isolated and fixed base structures and to observe the effect of seismic isolation on the weight of the structure by comparing the results. For the research, 4 2D steel frames and 4 3D space steel frame models were designed. Each frame model is considered both seismically isolated and fixed base. For seismic isolation, triple friction pendulum isolator bearings, which are friction-based isolator devices, are used. An optimization program has been developed based on artificial bee colony, crow search and Archimedes optimization algorithms for optimum designs. Limiter functions are inter-storey drift, top story offset, strength and geometric constraints and LRFD-AISC regulation has been complied with for these constraints. As a result of the optimization analyses carried out, it was observed that seismic isolation significantly reduced the weight of the structures.