Evaluation of the effect of different seismic isolators on the behavior of asymmetric steel sliding structures

Abstract

Isolation of buildings from earth vibrations is a new method that has been considered in the last few decades and is the only way to reduce simultaneously the inter-story displacement and acceleration of stories. In this method, increasing the period of rotation and damping of the structure at the separated level, the energy from the earthquake force to the structure decreases. Furthermore, recent earthquakes, including the Bam earthquake, have horizontal and vertical components, which resulted in the destruction of more structures, depending on the time of the start of the vertical or horizontal components or their combination. This issue highlights the importance of examining the vertical component of the earthquake in addition to the horizontal component. According to the mentioned cases, the main objective of this research is to investigate the behavior of asymmetric sliding structures with different separators under the horizontal component and the combination of horizontal and vertical components of the earthquake, taking into account the effects of soil and structure interaction. For this purpose, structures of 1, 5, and 10 stories irregular building(irregular amount of 40%) with seismic separators R-FBI, LRB and P-F on soil type IV are considered. In order to obtain the results of the research, the numerical method of finite element method has been used with modelling of materials in nonlinear area and performing explicit dynamic analysis. The results of the study showed that with increasing number of stories, the seismic separation function of R-FBI is better than other LRB and P-F separators. Also, the results of this study show that the simultaneous effect of horizontal and vertical components on structures 1 and 10 is remarkable.

Keywords

• sliding structure
• isolator
• seismic analysis
• steel moment frame
• finite element method