Research On Key Technology And Engineering Application Of Frame Structure Foundation Isolation Design

Seismic isolation technology is more and more used,the commonly used isolation device has friction skateboard support,laminated rubber support,the effective combination of a variety of different isolation devices,can play their own advantages,play a good role in isolation.At present,the application of combinatorial isolation technology is more and more extensive,but the research of its theory is not very sufficient.Based on this,the paper collects the literature on combinatorial isolation,understands the development of combined isolation technology at home and abroad,the mechanical properties of rubber bearing and the calculation and analysis method of isolation structure,and studies the design method of isolation structure and the construction measures of isolation building,hoping to promote the development of combined isolation technology.Taking a 6-layer frame structure as the research object,this paper makes modal analysis and nonlinear time-history analysis of three kinds of working conditions of traditional seismic structure,pure friction slip isolation structure and parallel combined foundation isolation structure by using ETABS finite element program.The parameters of seismic Response index are obtained,including interlayer shear Force,interlayer displacement and floor absolute acceleration.Modal analysis shows that after setting the isolation layer,the self-vibration period of pure friction slip isolation and combined isolation structure is extended by more than twice times,which makes the difference between the excellent period of the site and the vibration period of the structure greatly,and reduces the possibility of resonance.The vibration data show that the superstructure of the isolation structure is almost horizontal overall movement,there is displacement mutation in the isolation layer,the relative displacement between the floors is very small,and the traditional seismic structure because of the superstructure and foundation consolidation,the relative displacement between the floors is large,showing the shape of shear deformation.The nonlinear time-history analysis of frame structure under the action of multiple and rare earthquakes shows that the interlayer shear force,interlayer displacement and the absolute acceleration of the floor of each layer of the isolation structure are obviously reduced,among which the seismic isolation effect is the most obvious,which shows that the isolation bearing has the function of filtering,so that some spectrum components in seismic waves can not be transferred The dynamic response of the upper structure under earthquake is greatly reduced.In the combined isolation structure,the main factors affecting the combined isolation effect are: friction coefficient of friction skateboard and the number of friction skateboard.The results show that the period of the structure decreases with the increase of the friction coefficient of the skateboard bearing,and the period of the pure friction slip isolation structure is greatly influenced by the friction coefficient of the skateboard bearing,and the variation of the period with the friction coefficient is smaller when the combined isolation of the lead rubber bracket and the friction slip support is used.That is,the friction coefficient of sliding support during parallel isolation(lead rubber bearing)has little effect on the period of the structure.It is defined as the gravity load ratio of the upper structure,that is,the number of skateboard support,which is borne by the friction slip isolation bearing.The results show that the self-vibration period of the parallel combined foundation isolation structure increases with the increase of the value,and the change trend of the amplitude and absolute acceleration amplitude of the interlayer displacement increases with the increase of the value.These practical conclusions can provide guiding opinions for the design of combined isolation in the future.