Dynamic response and time-varying damage analysis of complex connected structures considering uneven foundation settlement

To study the dynamic response and the time-varying damage law of irregular and complex connected structures on the eastern annex of Xi’an Railway Station under earthquake actions, a finite element model (FEM) of the connected structure was established using SAP2000 software. The force law and damage mechanism of the upper structure under uneven settlement of the foundation were discussed, and the influence of earthquake action on development process of structural plastic hinges, internal forces of key components, inter-story shear force and inter-story displacement angle was analyzed. The research results show that uneven settlement of the foundation can increase the internal forces and damage degree of key components, and the small triangular area produces more plastic hinges, exhibiting obvious translational-torsional coupling effects. In addition, during the elastic-plastic loading stage, the maximum inter-story displacement angle of the connected structure is less than the maximum limit value specified, and the inter-story shear force in the small triangle area is more significantly affected by uneven settlement of the foundation. Due to the ability of sliding supports to release the relative displacement of connected structures, they can effectively alleviate the adverse effects of uneven settlement of supports on the seismic performance of connected structures.