Research On The Mechanism Of Story Isolation Structure

The mechanism and seismic response regulations of story isolation structure are studied in this thesis. The main parameters which affect the effect of isolation and the design method of story isolation structure are proposed. The analysis results show that the mechanism of story isolation structure has been significantly influenced by the location of the isolation layer. When the location of isolation layer is approach to the base of structure, its mechanism is similar to that of base-isolation structure; And when the location is approach to the roof of structure, its mechanism is similar to that of the Turned Mass Damper (TMD). The two kinds of mechanism are very different. At the same time, the analysis results also show that the main parameters affecting the isolation effect of story isolation are lateral stiffness,location and damping ratio of isolation system. In general, the lower of the isolation system and the larger damping ratio, the better isolation effect. There are four chapters in this thesis.In the first chapter, the development and current situation of story isolation are summarized, including its applicable range,its advantages,its applications in practical engineering. And the contents and significance of this thesis are provided at the end of the chapter.In the second chapter, the mechanism of story isolation is studied. Firstly, the mechanism of base-isolation and the mechanism of TMD are introduced respectively. Secondly, after the mechanical model and the dynamic differential equation of the isolation structure are set up, the formulas of the relative displacement and the absolute accelerative speed are deduced by the random vibration theory. And the mechanism of story isolation is summarized.In the third chapter, the seismic response of story isolation structure is analyzed by the numerical method. The dynamic model is set up. The seismic response of story isolation structure are calculated under different seismic wave by changing the main parameters. The results of calculation are analyzed. The regulations of seismic response of story isolation are summarized.In the fourth chapter, according to the results from the second chapter and the third chapter, the main parameters which affect the effect of isolation are proposed, and their optimum value are obtained. In the end, the design method of story isolation structure is proposed, too.Finally, some conclusions are generalized at the end of this thesis.