Study On Seismic Performance Of Assembled Frame Structure Under Near-field Earthquake

Prestressed fabricated joints with additional angle steel are dry joints.They do not need cast-in-situ concrete.They can effectively reduce the workload on site and facilitate the construction of the whole fabricated structure.As a fabricated building,the joints themselves often fail first and withdraw from work under earthquake.As a kind of seismic action different from far-field earthquake,near-field earthquake has more destructive effect than ordinary far-field earthquake,and has obvious characteristics in seismic wave characteristics.In this thesis,the assembled building with additional angle steel is taken as the research object,and its seismic performance under near-field earthquake is mainly discussed.In order to study the seismic performance of the fabricated concrete frame structure with additional angle steel under near-field earthquake,the research work in this thesis includes: consulting a large number of literatures,understanding the research on fabricated buildings at home and abroad,especially on the treatment of fabricated building joints,researching on near-field earthquakes,understanding the characteristics of near-field earthquakes and steel knots through consulting literatures.Structural behavior of buildings or bridges under near-field earthquake is studied to understand the seismic response of these structures under near-field earthquake.Through literature review,the laws and characteristics of near-field earthquakes are summarized.Through PEER website,15 groups of specific representative near-field seismic waves are selected according to the research content for later modeling and simulation analysis.The characteristics of assembled joints with additional angle steel are introduced.Based on Professor Han Jianqiang's experimental joints,the reliability of the joints is verified by OpenSees software.On this basis,a fivestorey prestressed frame structure with additional angle steel is established,and a five-storey cast-in-place frame is established.The overall seismic performance of the two structures is discussed by Pushover analysis.The dynamic time history of the structures is analyzed by using 15 selected groups of Near-Field Seismic waves,and the seismic performance of the pre-stressed assembled frame structures with additional angle steel under these seismic actions is analyzed.The results of this thesis show that due to the large vertical effect of near-field earthquakes,the cast-in-place frame structure will have excessive vertical displacement,which will cause great earthquake damage;while in the pre-stressed assembled frame structure with additional angle steel,angle steel as an additional component can provide a good energy dissipation effect,and improve its seismic performance.The pulse generated by the unique fault motion of near-field earthquakes will affect the structure.It produces a resonance-like effect,enlarges the displacement of the structure,and enhances the NearField Seismic destructive force.