Research Of A Method For Incremental Dynamic Analysis And Its Application In Tall Building Structures

Structural failures in recent earthquakes have exposed weakness of current design procedures.Along with the further development of human practice and earthquake resistant engineering technology, seismic design theory has also been changing and improving from time to time.Under such background,the scholars of the United States and Japan have proposed the philosophy of Performance-based Earthquake Engineering (PBEE) design,the basic thought of which is making the structure designed satisfied with the expected performance objects during the lifetime.Elastic-plastic analysis is an important part of performance-based seismic design. Among the existing methods,nonlinear static analysis (pushover) method and incremental dynamic analysis (IDA) method which is based on dynamic time history analysis are regarded as the commonly used analysis methods of structural performance evaluation.The main studies and contents in this paper are as follows:A simplified analysis models of shear wall is introduced which is called multi-vertical-line-element model.Comparative analysis is performed through an example to verify the effectiveness of this model in the elastic stage.Then we use this model which is called the multi-vertical-line-element model and try to simulate the elastoplastic properties of the shear wall.The fast nonlinear analysis method (FNA) as a dynamic time history analysis method is introduced, the basic principle and implementation steps of this method are elaborated on, and compile example of two different heights of the frame structure to process dynamic analysis, confirmed this approach can complete dynamic analysis relatively quickly, provided assistance to the methods of the IDA.The basic principle, the parameters selection, the statistical methods and the definition of the limit-states of IDA curves for the IDA method are introduced in detail. The calculation process of the IDA method through the responses of a 14-story RC tube in tube structure is realized and the multiple earthquake records IDA curves is obtained. The limit-state capacities and different fractile IDA curves are also obtained according to the statistical method.The basic theory of fragility analysis is discribed in this paper.The calculation process of the fragility analysis is introduced and the problems of integration and fitting of the curve are also discussed.IDA method is applied to the seismic fragility analysis and the estimation of the limit-states. While combining the IDA's results with the seismic hazard curve, we can obtain the MAFs(Mean Annual Frequency) of exceedance for the limit-states,then the seismic behavior of structures under a rare earthquake can be estimated.