| Earthquake is a kind of natural disasters with strong destructive power, when an earthquake occurs, it will cause serious damage and even destruction on the building structure and facilities in it’s scope of the impact. The earthquake itself exists great uncertainty, and the factors to influence the characteristics of earthquake ground motion is very complicated, it causes that, the dynamic response and damage degree of a structure under the effect of different ground motions shows a great difference. This paper mainly discusses the influence of earthquake epicenter distance to the characteristics of earthquake ground motion, and the difference of structure dynamic response under the ground motion with different epicenter distance.Main work include:Choosing11single direction ground motion records according to the definition of near field and far field earthquake respectively, do some preliminary processing to the original acceleration records such as baseline correction, calculating the velocity and response spectrum of the ground motion, comparing the difference between the characteristics of two kinds of ground motion; Building up a nonlinear dynamic analysis model of a plane frame of6, simulating the nonlinear behavior of components with fiber cross section in the Perform-3d application; Using the selected ground motion records for incremental dynamic analysis (IDA) of the structure, statistical processing the calculation results, comparing the structure dynamic response under the ground motion of near field and far field for their difference, then analysis the possible cause of the difference.By comparing the selected two classes of ground motion, we found that the near field earthquake have obvious pulse characteristics, and compared with far field earthquake, it has a longer period of acceleration response spectrum peak, the decline is relatively flat, his can cause bigger seismic action on structure; By comparing the structure dynamic response under the two kinds of ground motions, we found that, with the same ground motion intensity, near field earthquake will cause bigger displacement response and but smaller internal force response, under the ground motion effect with stronger pulse characteristics, Structure will behave to be easier to yield and faster to limit state. |
