The Application And Anti-seismic Research Of Friction Dampers On The Technology Of Adding Steel Storys On The Top Of Frame Structure

Retrofitting the structure with steel in floor technology is widely used in floor-addingand retrofitting of building because of its property such as light mass, high strength,convenient for construction and less impact on the original structure. While the originalstructure is mostly masonry or reinforced concrete frame structure which results in atypical "soft" on the vertical irregular structure, differences occur in the mass, stiffness,period and damp ratio after storey-adding. And for this kind of transfinite structure thereare no clear and unified norms and standards in our country to refer to. In this paper，byusing the finite element analysis software energy dissipation device—friction dampersare set on the diagonal brace of this additional layer with the combination of astorey-adding transformation example to analyze the change rule of displacement,inter-story displacement rotation and inter story shearing force of the integral structureunder frequent earthquake and rare earthquake. It is shown that when adding four layersof steel structure on the top of multi-storey concrete frame structure，the phenomenon ofwhippy twig effect is very obvious; Friction energy dissipation brace system effectivelyreduces excessive lateral displacement and changes the vibration characteristics of theoriginal structure, reducing the earthquake input energy so that the whole structure canmeet seismic code requirements. At the same time, based on large amount of calculationand analysis about two important parameters—sliding displacement ratio and initialstiffness ratio of the friction damper, its energy dissipation effect is obtained and thestudy provides certain theory reference for the application and design of frictiondampers in storey-adding transformation.