Research On Displacement Response Spectra Of Different Site And Its Application In Seismic Calculation Of Structures

The performance status of the building is decided to extent of the damage to its components in earthquakes, while the component damage is closely related to structure of inter-story displacement response and deformation. People naturally design structure and components with displacement parameters as a target, so as to make the building satisfied with the expected performance level, which resulted in displacement-based seismic design theory.Maximum elasto-plastic displacement response and deformation component of the structure is to assess the performance of non-linear state (which can repair, the collapse, etc.) of structure,and it is one of the key indicators. It is the first step in achieving the performance-design for solving the seismic inelastic displacement demands of structure. Therefore, research on inelastic displacement spectra has profound engineering significance and broad application prospects.The main studies and contents in this paper are as follows:The formula of standardized displacement ratio spectra is established in which soil site, design characteristic periods and damping are considered. And the influence of damping, hysteretic model, stiffness reduction factor a, P-â–³effects and near-fault velocity pulse on the elastic-plastic displacement spectra is analysised. Then the influence of damping, hysteretic model and the stiffness reduction factor a on ductility demand spectra is analysised.Direct displacement-based seismic design method is introduced, and the basic theory and procedure of the method are described in detail. The method through the responses of a 10-story frame structure is realized, and it can effectively control the structure response under earthquake excitation by taking the displacement which confirmed into control,and it is separated to the traditional force-based seismic design.The formula of elastic displacement spectra under bi-directional earthquake excitation is established in which soil site, period ratios of two principal axes and damping are considered. The influence of displacement ratio spectra of constant strength (period ratios of two principal axes, damping, stiffness reduction factor a and different ground motions) is analysised. Then, the ductility demand spectra for bi-directional earthquake motions is established. N2 method (firstly developed by Fajfar:two methods of nonlinear analysis) and multiple-mode pushover analysis methods (MPA) are regarded as the commonly used analysis methods of the three-dimensional nonlinear static analysis (pushover) methods. And the basic theory and procedure of capacity spectrum method for multi-dimensional are described in detail. According to the acceleration spectrum in the current Seismic Design Code, constant ductility demand spectra with Ay-D format which can be applied to the capacity spectrum method for multi-dimensional is established.