The Strengthening Design And Seismic Performance Analysis Of Steel Frame After Local Collapse

Due to the reason of special factors of China, material’s durability and disaster, some existing steel frame need to be reinforced.With the steel frame made oftruss girder as engineering background, the article uses finite element software to make a comprehensive analysis of steel frame after local collapse happened, including: the investigation analysis of steel frame before strengthening; The analysis of Truss girder joint;The dynamic response of steel frame under the response spectrum and elastic time history analysis;The calculation of concrete composite reinforcement method.1) Through the investigation of the scene of the accident and calculation result of whole model, the structure has a relatively comprehensive analysis: The performance analysis of fractured joint;The major truss girder; Seismic analysis of the structure before strengthening.2)In order to find a more proper and cheap method for the strengthening of steel structure and to provide a similar method to analogous structure. In this article,using three types of reinforcement method to calculate the modeling. The consideration includes the result of calculation and analysis, the construction cost, the selection of material and construction duration and other factors.3)The measure of truss beam reinforcement are: Adding the welding plate and angle steel to rehab the terminal of truss girder;Calculating the strengthening structure by hand and computer respectively to make sure the reinforcement project is safe; Using finite software Abaqus to assess the six group component at different reinforcement degree;Selecting the most reasonable method and using finite element software to assess the seismic behavior.4) Because the steel frame is on the stage that the concrete has not been pouring, a composite strengthening method that the truss girder is transformed into composite beam and the steel column is wrapped by the outside concrete is put forward.In the finite element software of Midas Gen 8.00, calculating bearing capacity of pure steel beam on the construction stage and of composite beams and steel reinforced concrete column on the normal use stage. Final, calculating the story drift of whole structure’s dynamic performance on the small earthquake.The article summarizes several common steel frame reinforcement method including composite scheme which provide an idea to similar structure and has some engineering application value.