Capacity Spectrum Method Research And Engineering Application In Performance Based Seismic Design

The concept of performance based seismic design has been gradually accepted by the earthquake engineering profession recently, which is to design a structure so that it will perform in a specified manner when subjected to various loading scenarios and to provide owners and designers with capability to select alternative performance goals for the design of different buildings. Compared to the current design codes, performance based seismic design stresses cost-effectiveness criterion as one of the most important principles and more attention is paid to the structural performance at the inelastic stage. As an effective analysis method of performance based seismic design, Capacity Spectrum Method has made a lot of developments in recent years, butits research is only in the preliminary stage in our country. Thus, the theorical research and engineering application of Capacity Spectrum Method combined with Chinese seismic design code is very important, which is the aim of this thesis.As a simpilfied seismic analysis method, Capacity Spectrum Method should follow the principles of the structural dynamics in theory and satisfy the need and experience of the practical engineering. Considering the inadequate understanding and non-uniform fomulations of Capacity Spectrum Method in the research and application profession in China, The present thesis assembles the module of Capacity Spectrum Method with ANSYS software based on the procedures in ATC-40, which has been employed by the seismic design code in the US. The results may be helpful to understanding and application of Capacity Spectrum Method in ChinaCapacity Spectrum Method is generally suitable to the structures whose dynamic response is dominated by by the first mode. The structure with lower weak story is relatively stiff in the upper stories and flexible in the lower stories, and the first vibration mode is dominated. The thesis performs the anylysis with Capacity Spectrum Method and optimization design for the structure with lower weak story, which is helpful for the engineers to make the rational design.High damping of the isolators produces some difficulty in the analysis of the based-isolated structures by Capacity Spectrum Method. Considering the common measure of equivalent damping used by the Capacity Spectrum Method in ATC-40 and the base isolated to reduce the earthquake action, this thesis employes Capacity Spectrum Method in the annlysis of base isolated structures with special-shaped columns and short-limb walls and performs the optimization deisn according to the cost-effectiveness criterion, which is helpful to the evaluateon of the performance and economy for this type of structure.