Research On Seismic Fragility Of RC Frame Structure With Considering Seismic Motion Characteristics

In recent years,several strong earthquakes occurred at home and abroad(such as Chi-Chi earthquake,Wenchuan earthquake,etc.)caused many building collapse and casualties.The collapse resistance of structures under the action of strong earthquakes has been widely concerned by the engineering community.The vulnerability analysis and collapse resistance analysis based on IDA are very sensitive to ground motion input.At present,most of the researches on the collapse resistance of RC frame structures are carried out under the action of common far-field earthquakes and non-pulse earthquakes.Therefore,it is very important to analyze the pulse-type seismic characteristics and study the influence of pulse-type seismic characteristics on the collapse resistance of RC frame structures.This paper mainly carried out the following research:(1)Chapter one introduces the research status of pulsed seismic characteristics,IDA based vulnerability analysis and collapse resistance of RC frame structures.(2)According to Baker suggested method by wavelet analysis to identify the ground motion,identified 65 pulse-free ground motions and 80 pulse-type ground motions from PEER database.These ground motions are classified into bedrock,hard soil and soft soil according to the site type.The amplitude(effective peak acceleration of vibration analysis of EPA,effective peak velocity of EPV,characteristic cycle of Tg,the peak acceleration of PGA,the peak speed of PGV,ratio of peak values of PGV/PGA),frequency spectrum(acceleration amplification beta spectrum,velocity response spectrum,Fourier spectral superior frequency)and significant duration characteristics(acceleration integral significant duration and velocity integral significant duration)of the two types of ground motions are compared.(3)Chapter three introduces the basic concept,analysis method and theory of incremental dynamic analysis.Selection pulse-free ground motions and pulse-type ground motions records each 10 from 65 pulse-free ground motions and 80 pulse-type ground motions which identified from the second chapter.20 seismic record as input using SAP2000 to the design of the 5,10 and 15 layer RC frame structure analysis of IDA,compared to two classes under the action of earthquake response of the RC frame structure difference,study two kinds of RC frame structure seismic response characteristics under the action of earthquake.(4)Chapter four introduces the basic concept,analysis method and theory of vulnerability analysis.On the basis of chapter three,IDA vulnerability analysis is carried out on the three RC frame structures of 5,10 and 15 floors.The collapse resistance of RC frame structures subjected to two types of ground motions is evaluated by using collapse reserve coefficient.