Seismic Performance Analysis Of Base Isolated Frame Structure Based On Endurance Time Method

At the present stage,China’s earthquakes show observable characteristics of high frequency and intensity,while most earthquakes are shallow earthquakes,focal depth in the general dozen of kilometers or so.China’s population density of some provinces,such as: Taiwan,Fujian,Sichuan,are relatively high frequency of earthquake eruptions in the provinces,half of the city is in the area of frequent earthquakes,if the earthquake will cause extremely serious losses and casualties.Therefore,in the building structure design phase,seismic action should be considered,and the endurance time method as a new method for seismic analysis,can not only consider the influence of high-order vibration mode,and can be ideal forecast structural seismic performance under different seismic intensity,the method is characterized by its seismic intensity of the time history curve used growth increases over time,and a large number of studies have shown that this kind of analysis method of the calculation results are accurate,and compared with IDA method,it greatly improves the computational efficiency.1.Based on the code of seismic design in China,three endurance time acceleration curves for 30 s are synthesized by using the least square method,and their acceleration response spectrum,velocity response spectrum and displacement response spectrum are compared with the code response spectrum respectively.2.Taking a 15-story base-isolated reinforced concrete frame structure as an example.IDA analysis under the action of 10 natural seismic waves and the endurance time history analysis under the action of 3 endurance time history are carried out for the structure.The response of the maximum displacement of the peak,the maximum base shear,the maximum interlayer displacement Angle and the maximum displacement of the isolation layer under different earthquake intensities are compared.3.Through the analysis of structural seismic vulnerability research,obtained by the abscissa denotes the seismic time of seismic vulnerability curve,and the interlayer displacement Angle as a parameter in structural earthquake damage probability formula,the structural damage index is obtained under different seismic time expectations,which can be used as the basis of structure damage assessment.4.Based on the analysis of the possible impact of an earthquake on the financial risk of buildings,the corresponding risk assessment criteria are summarized,which can be further expressed as quadruple integral.Based on this method,the annual expected loss of structural models based on IDA and endurance time method is calculated.