Stiffness adjustment and seismic performance analysis of stilted frame structure based on isolation bearing

Abstract

The uneven lateral stiffness between the bottom columns of the stilted frame structure is caused by the fixed foundation with different heights. It is a new idea to adjust the uneven lateral stiffness of this kind of structure by setting isolation bearings. In this paper, the effectiveness of adjusting the lateral stiffness non-uniformity between the bottom columns of the stilted frame structure based on the isolation support is analyzed theoretically. Two calculation examples of the stilted frame structure with different slopes and six corresponding calculation examples of the stilted frame structure with isolation support are designed. The seismic response characteristics of eight example structures, such as shear and moment distribution in the bottom column, structural shear and inter story displacement are analyzed through the method of elastic analysis and elastic-plastic time history analysis of the structural mode decomposition response spectrum, and the effectiveness of reasonable selection and layout of isolation bearing in adjusting the non-uniformity of lateral stiffness between columns of this kind of structure is further discussed. The results show that: The uneven lateral stiffness of the bottom column of the stilted structure can be adjusted effectively by the reasonable arrangement of isolation bearings, the shear force of the bottom short column of the stilted frame structure can be reduced significantly, and the local damage of the hanging foot short column can be avoided. At the same time, the overall seismic response of stilted frame structure can be reduced and its torsional effect can be improved by the arrangement of isolation bearings.