Seismic Research Based On IDA Of RC Frame Stucture Designed By The New And Old Codes

With the rapid development of China’s economy, the construction industry has entered astage of takeoff. With the progress of science and technology, its design specifications havebeen constantly reveised and perfected as time goes by. In the context of frequentearthquake disasters, the latest “Code for Seismic Design of Buildings” GB50011-2010wasissued and carried out, which means a new stage for the antiseismic design of buildings.However, many existing buildings had been constructed according to the old antiseismicspecifications. Therefore, the antiseismic properties of architectural structures designedaccording to the old or new antiseismic specifications draw a lot of attention.The most common structure of reinforced concrete was chosen as research object fromdifferent types of architectural structures. The incremental dynamic analysis was adopted tocompare the antiseismic properties of the frame structures designed respectively accordingto three versions of the antiseismic specifications namely GB50011-2010, GB50011-2001,and GBJ11-89. The main contents are as follows:(1)Improve the traditional incremental dynamic analysis. Select the seismic waveaccording to the characteristic period of ground motion on one hand and select the seismicwave at random on the other hand, and then the effects on the discreteness of IDA resultswere compared. It showed that the discreteness of IDA results obtained by selecting seismicwave according to the characteristic period of ground motion is significantly lower. Basedon this method, when the seismic wave is selected according to different characteristicperiods of ground motion to compare the effects on IDA results, it is suggested that thecalculation methods of seismic waves in FEMA-450be given priority.(2)Through the analysis of the reinforced concrete frame design in the three versions,the differences between the antiseismic material regulations, site classifications, seismiccalculation regulations, internal force calculation, and construction requirements arecompared. The results show that, the strength design of architectural structures in elasticstage has been enhanced, and meanwhile the ductile design of architectural structures inelastic-plastic stage has been paid more attention to.(3)According to the antiseismic regulations of10edition,01edition,89edition,the structure was designed and the model constructed of the same reinforced concretestructure. Through the improved incremental dynamic analysis, plastic hinge distribution, IDA curve results, collapse margin ratio, IDA curves’ vulnerability of the three structuresare compared. It comes to the conclusion that the structure designed according to10editionhas better antiseismic properties.(4)The antiseismic reinforecement scheme of using steel support was applied to thestructures of01edition and89edition which had comparatively poor performances. Theantiseismic properties of the two structures strengthened and unsrengthened were compared.And it comes to the conclusion that the steel-support reinforcement effecitvely improves thetwo structures’ bearing capacity to a certain extent, but reduces their ductility.