Application of 3D FE-IE Method for Seismic Soil-Structure Interaction Analysis of Space Truss Roof

This paper investigates the influence of soil-structure interaction (SSI) on seismic responses of long-span space truss roof. First, a three-dimensional (3D) integral finite element (FE) model of a typical regular pyramids space truss structure consisting of space truss roof and support columns is developed. By applying FE method for near field soil and infinite element (IE) method for far field unbounded soil, a comparative model including soil, foundation and space truss structure is also established. Then, modal analysis and time history analysis for the comparable models are carried out respectively. For space truss roof, the results show that horizontal displacement of truss roof and axial force in some chords near columns increases remarkably for considering SSI effect. Therefore, based on conventional seismic design without the consideration of SSI effect, it is suggested that these disadvantageous influences should be taken into account.