Isolation Measures And Effect Analysis Of Multi-tower Structure With Iarge Chassis

China is one of the countries suffering from serious earthquake disasters.Every major earthquake brings not only hundreds of millions of property losses to the country,but also a large number of casualties.Accordingly,people still need deeper understanding and understanding to earthquake disaster.At the same time,with the rapid economic development,there are more and more structural forms of buildings.In order to meet the needs of large-volume buildings,the large-sized multi-bottom tower structure emerges as The Times require.In high intensity area,it is common to apply isolation technology to large chassis multi-tower structure.This paper,taking a large basement high intensity training building as the background of the tower structure,embedded structure fixed end±0.000,set in the basement roof isolation layer is set on the basement roof,on the basement roof towers using seam vertical shock isolation processing,three tower the tower separation model is adopted,according to senior monomer base isolation analysis,a good solution to the irregular large chassis consists of isolation layer cause structure of eccentric mass,stiffness,structure simplifies the calculation,the structure of the power transmission way clear.First,verify the accuracy of numerical simulation.Through the choice of the form of isolation and determination of isolation target for the reasonable arrangement of the isolation layer,and then using large-scale finite element analysis software ETABS program,established large chassis training floor of the tower structure of isolation structure and isolated structure three dimensional finite element model,and use the YJK software from quality,cycle,interlaminar shear three aspects for accuracy checking.Secondly,the dynamic characteristics of the structure are analyzed.The model was judged by the three indexes of natural vibration period,mode mode and mass participation coefficient.Seven seismic records were selected and the seismic performance of each tower under frequent,fortified and rare earthquakes was analyzed by fast nonlinear time-history analysis(FNA)method.Under severe earthquake,compared before and after each tower isolation shear ratio,shear ratio,displacement Angle of three indicators,shear weight than meet the requirement of not less than 0.048 specification values,and the isolation layer shear force ratio between before and after reasonable distribution of 0.3-0.4 range,under article 7earthquake records,the tower after the quake insulation displacement Angle along with the development trend is basically the same floor,far less than the displacement Angle of the isolation structure,away from the specification limits,the tower isolation after isolation design,damping effect is remarkable,the isolation layer of rational design,the scheme is feasible;Under earthquake resistance of the structure and the structure of the isolation layershear force and overturning moment between between floor has carried on the comparison and analysis,and concluded that the main tower,west tower,east tower level to the damping coefficient is 0.38,0.38,0.36,respectively,thus determining the main tower,west tower and east tower horizontal seismic action,seismic construction measures can reduce the once,the tower structure under the action of earthquake resistance in isolation effect is significant.In the case of rare earthquakes,the displacement of the isolation layer and the tensile and compressive stress of the support are analyzed,and the interlayer displacement Angle is also analyzed.The maximum displacement of isolation layer of the main tower,west tower and East tower is 347 mm,371mm and 349 mm respectively,which meets the requirements of the specification for displacement.Under the simultaneous action of both horizontal and vertical earthquakes,the tensile stress and compressive stress of isolated rubber bearings are all less than 1.00 mpa and less than 30 MP,which meet the requirements of the code.The maximum inter-storey displacement angles of the main tower,the West tower and the East tower are respectively 1/437,1/361 and 1/481,which are all less than 1/200 and meet the requirements of the specification.After the isolation design,the towers also show good seismic performance under rare earthquakes.Finally,reasonable and efficient isolation measures are a powerful guarantee to achieve the isolation effect.Isolation measures are controlled by isolation construction measures and isolation structure measures to achieve the ultimate goal of isolation design.The isolation construction measures mainly include the construction principle,construction technology and the operation key points of seven technological links,etc.The construction difficulties include:the dense reinforcement of the lower pier leads to the inability to locate the sleeve bolt,the inaccurate positioning of the sleeve bolt,and the difficulty in controlling the reinforcement protection layer at the top of the lower pier.Finally,some practical solutions are given.Seismic isolation measures mainly include the connection of supports,isolation measures between towers and surrounding areas,isolation measures of stairs,elevators and pipelines.