Study On Seismic Isolation Technology Of Single Tower Structure With Large Chassis

The emergence of seismic isolation technology to a great extent promotes the development of seismic technology in China and provides a new idea for ensuring the safety of structures.Base isolation technology is a passive control system in which an isolation layer is set between the foundation and the superstructure.Now the development of base isolation technology has been relatively mature,the research of story isolation technology is a new direction of isolation research.Story isolation is a kind of isolation mode in which the isolation layer is set on the top of the column of the structure of a building.This isolation mode can not only reduce the seismic energy transmitted by the upper structure,but also is more flexible for the arrangement of the isolation layer.It is more suitable for some buildings with complex structure and higher requirements.For the large chassis tower structure with irregular vertical stiffness,the isolation layer can effectively reduce the damage degree of the structure and make the structure more safe and reliable by setting the isolation layer in the position of the sudden stiffness.In this thesis,the structural form and connection mode of the large chassis tower structure are introduced,and the research progress of the numerical simulation and simplified analysis on this subject at home and abroad is also introduced.Then,start to summarize some mechanical properties and calculation models of seismic isolators,establishment of simplified theory and dynamic equation of stratified seismic separation are summarized together.Through using the finite element software SAP2000 to set up two models respectively at the last,one is not set large chassis double aseismatic structure of isolation device,a large chassis and towers for the layer spacing between vibration model,both the two-way EL-Centro,Taft and Lanzhou wave input seismic waves,through the study of the modal analysis of structure and comparison,the analysis found that:(1)For the isolation structure of large chassis layer,the natural vibration period of the first three order is 2.8279 s,2.8183 s and 2.0108 s,respectively,and that of the non-isolation structure is 1.7453 s,1.6875 s and 1.4862 s.The natural vibration period is increased by about 1.62,1.67 and 1.35 times,respectively.Its natural vibration period is more than twice that of the traditional seismic structure,and avoids the excellent period of the construction site.(2)Through under the effect of different seismic waves to dynamic time history analysis of structures,the results found that large chassis structure of double layer interval shock model,its horizontal seismic response,compared with the traditional anti-seismic structure,average damping ratio can reach35%,proved the isolation layer damping effect is very obvious.