Effect Of Link Beam Connected On Top Of Basement Columns On Stability Of Serial Isolation System

Recently, isolation structure becomes important developing path in seismic protection engineering. The laminated rubber bearings of isolation system are used widely in the world. Considering application of serial isolation system is extensive in fact and deformation between bearing and columns not only interact obvious but also influence mechanical behavior of integral isolated structure at the same time generating second-order effects. This make analysis of the whole of serial isolation system becomes very important.At present, the laminated rubber bearings are often mounted on the top of the basement cantilever columns in most of projects in china and abroad, but due to various factors, the series of a laminated rubber isolator and cantilever column was rarely considered as whole. The deformation of bearings and columns can bring in second-order effects as the function of horizontal seismic force and vertical load. Simultaneously influence the stability of isolated buildings. During the design of base isolated buildings with basement, three major methods are used in the design of substructure:single column, single column plus link beam and single column plus shear wall with short piers. Only the former two design options are comparison analyzed in this paper. First, the second-order displacement of series seismic isolation system is calculated through Rayleigh-Ritz way based on energy theory under the condition of small distortion. Second, the geometrical nonlinear curve of horizontal capacity-displacement and vertical capacity-horizontal displacement of series seismic isolation system is concluded through ABAQUS software. At last, the two design options of substructure of base isolation buildings are compared quantitatively through the finite element models and theories analysis at the same time obtain the destruct mode. It can be found that the single column plus link beam structure is better than the single column at the performance of horizontal capacity, vertical capacity and stiffness etal. This study can be used for reference during the design of base isolation buildings for selecting the type of structures.