Pushover Analysis Of Upper Structures Considering Pile-Soil-Structure Interaction

Pile-soil-structure dynamic interaction analysis is one of the key subjects in geotechnical earthquake engineering at present. At this stage, most of research work on upper structure’s seismic response with consideration of pile-soil-structure interaction is based on nonlinear dynamic time-history analysis method. However, nonlinear dynamic analysis is not widely used in practical projects because of its complicated theory, large calculation workload, difficult convergence and higher quality demands for the researchers.With the development of performance-based seismic design method, Pushover method grows up gradually. Pushover method is a kind of static nonlinear calculation method used to approximatively evaluate the seismic performance of structures, which have many advantages such as simple concept, easy operation and high efficiency calculation. This paper analyzed a upper structure’s seismic response considering pile-soil interaction by Pushover method. The main work is as follows:(1) The basic principle, specific implementation ways, lateral load patterns and the method to determine the target displacement of Pushover method were systematically presented. Then, the characteristics and implementation notes of the finite element software SAP2000and the implementation procedure of Pushover analysis in software SAP2000were elaborated in detail.(2) Lateral load patterns are important influence factors of the Pushover analysis. The static Pushover analysis with seven different lateral load patterns was applied to a ten level plane frame structure located in rigid foundation, which is compared with the nonlinear dynamic time history analysis. The results show that there was little difference between the results of different lateral load patterns for the structure mainly controlled by the first vibration model, and the reversed-triangle loading mode was recommended.(3) The finite element model and the winkle beam model which are usually used to analyse pile-soil-structure interaction are elaborated in detail. The plane nonlinear Pushover analysis was carried out to analyse the pile-soil-structure interaction. Then a contrast with the result of the nonlinear dynamic time history analysis was done. The results show that the difference between the results of Pushover analysis and these of the nonlinear dynamic time history analysis is little, the winkle beam model with correct spring stiffness parameters can take place of the finite element model to analyse the upper structure’s seismic response with consideration of the pile-soil-structure interaction.