Isolation Efficiency Analysis On Self-isolated Structure Of Pengzhou Middle School's Dormitory Building

China is one of the countries with the most severe earthquake disasters in the world,so improving the seismic performance of buildings is an effective means to reduce structural damage.At present,the base isolation is a conventional passive control,which is an effective way and method to improve the seismic performance of the building;the self-isolation structure is no additional isolation device,and its own components are used as isolation components to reduce the self-isolation layer Stiffness extends the natural vibration period of the structure and keeps it away from the excellent period of ground motion,thereby reducing the seismic response of the superstructure.The self-isolation structure of the concrete-filled steel tube column relies on the concrete-filled steel tube column as the self-isolation member,and there are few studies on the self-isolation efficiency.Therefore,taking the self-isolation structure of the dormitory building of Pengzhou Middle School as the engineering background,the self-isolation efficiency analysis was carried out through numerical analysis,and the design points of the self-isolation structure of the concrete-filled steel tube column were proposed.(1)Combined with the self-isolation structure of the dormitory building of Pengzhou Middle School,the dynamic balance equation of the self-isolation structure of the concrete-filled steel tube column under the earthquake is established.Through the simplified single-degree-of-freedom model of the self-isolation structure,the key parameters(stiffness /equivalent stiffness,blocking gap,Blocking position)on the impact of structural acceleration and displacement,study the seismic isolation mechanism of concrete-filled steel tube columns.On this basis,the design points of the self-isolated structure of concrete-filled steel tube columns are put forward in conjunction with relevant codes.(2)In order to discuss the isolation efficiency of the self-isolated structure of the dormitory building of Pengzhou Middle School,combining its design drawings and dynamic test data,the self-isolated structure of the dormitory building of Pengzhou Middle School(referred to as the self-isolated structure)and traditional steel bars were established using finite element software For a nonlinear finite element model of a concrete structure(referred to as non-isolated structure for short),two actual ground motions and one artificial ground motion are selected to analyze the nonlinear seismic time-history response of the above two models.It is concluded that the self-isolated structure of the dormitory building of Pengzhou Middle School can not collapse under the action of large earthquakes and super-large earthquakes,and can reduce the acceleration response of the superstructure by 1/3,and the self-isolated concrete-filled steel tube members are lightly damaged.(3)In order to explore the impact of the collision gap on the superstructure,three sets of collision gaps of 25 mm,16mm,and 8mm were taken to establish a nonlinear finiteelement model,named model 1(that is,a self-isolation model)and model 2 respectively.And model 3,and select two actual ground motions and one artificial ground motion to analyze the nonlinear seismic time history response of the above model.It is concluded that the blocking structure can reduce the inter-layer displacement of the first layer(self-isolation layer)of the structure after the limiting function,and prevent the structure from collapsing.As the blocking gap decreases,the limiting effect increases;but the acceleration and displacement response of the upper structure Increase and decrease the isolation effect of the self-isolated structure.