Anti-eatrhquake Performance Of The Irregular Adding Storey Structure With Buckling-resistant Braces

At present the shortage of housing, the cost of demolition and reconstruction is very high,especially in urban area, adding stories is more and more paied attention by researcher.Sometimes adding stories, reinforcing very low seismic fortification criteria of the originalstructure, it not only expand the use area of the original construction, but also improvingearthquake-resistant performance of building.The technique of adding stories with steel structures is gradually promoted to be a newtype of structural reinforcement for its advantages of light weight, good earthquake-resistantperformance and easy construction. because after adding stories earthquake-resistantperformance of the original structure lessen, the original building don not satisfied existingnational standard, so the bottom of original construction must be reinforced. TheBuckling-Restrained Brace(BRB)is a new kind of brace focusing on the solution to theproblems associated with buckling．The concept of the BRB is the buckling prevention of thecentral steel core by encasing it over its length in a steel tube filled with concrete．Thecompression and tension loads are designed to be carded only by the core by means ofunbounded layer to allow the free slip between the core and the surrounding concrete．TheBRB can reach and retain fully sectional yielding of the core under compression．In strongerearthquake，it exhibits stable and predictable hysteretic behavior，provides significant energydissipation capacity and is an attractive alternative to protecting frames．After strong shock，the inelastic distortion of main structure is small，it is easily to replace the broken braces．In conclusion, according to above content, by means of ANSYS software a bottomirregular reinforced concrete frame is builded, which is adding stories with steel. Setting upBuckling-Restrained Brace reinforces entirety structure, research contents includes followingitems;(1)Sketching the design method and technology of adding steel stories; discussingMany kinds of methods of reinforcing original architecture; the calculation theory oftensional deformation of the irregular plane(2)On the basis of the previous formulae for Story displacement of irregular RC flame intensional effect. by means of setting up BRBs, it raises calculation methods of reinforcingirregular construction(3)Adopting ANSYS software to programming, The modal analysis and The dynamictime-history analysis must be made to the original adding storey structure and arrangingBRBs structures individually under the conditions of multiple or rare earthquakes, comparingto natural oscillation period ratio, story drift, tensional displacement ratio, tensional angle, thechange of the stress of beam and pillar and the dynamic response of the structure underdifferent damping ratio, which proves the calculation theory of control the torsion of structure according to arranging BRBs.(4)Building three different arrangements of BRBs, the analysis of natural oscillation periodratio and tensional displacement ratio, it reaches two principles of reducing tensional effectionof BRBs arrangement.