Motion Shape Control of Superstructure in Base-Isolated Tall Buildings using GBMO-Based Uniform Deformation Techniques

This paper proposes three techniques aimed at enhancing the seismic performance of base-isolated tall buildings through uniform deformation of the superstructure. The first and second methods focus on generating a uniform modal shape and an even distribution of seismic loads across the floors, while the third method seeks to minimize the standard deviation of story drifts. For these purposes, an optimization procedure based on a gas Brownian motion optimization (GBMO) algorithm is defined. Simulation results, compared to those for a ۲۰-story reference base-isolated structure, demonstrate that these techniques effectively reduce maximum floor displacement, particularly in the upper levels of the studied buildings. The proposed methods show clear advantages in lowering maximum floor drift, a critical factor in seismic damage. Specifically, methods ۱ and ۳ resulted in significant reductions in maximum floor drift, ranging from ۳۰% to ۸۰% in the upper floors. Additionally, these methods led to a reduction of ۱۰% to ۱۵% in maximum acceleration and seismic forces on the upper floors, while a slight increase was observed in the lower floors. Among the methods, method ۱ exhibited the best overall performance, yielding average reductions of ۶.۶۵%, ۳۲.۶۵%, and ۰.۸۸% in maximum floor displacement, drift, and acceleration, respectively, when compared to the reference base-isolated structure. While methods ۲ and ۳ resulted in only modest reductions in displacement and acceleration, they were effective in significantly lowering maximum floor drift.

کلیدواژه ها:

Base-isolated structure ، GBMO algorithm ، Motion shape control ، Seismic performance ، Tall building