Isolation Performance Analysis And Pilot Engineering Application Of Friction Pendulum Isolation Structure

Friction pendulum bearing isolation technology is one of the main methods of structural isolation.It is mainly used in bridges and building structures with relatively small height and width,and there are few studies on friction pendulum isolation structures with large aspect ratios.Because the friction pendulum isolated support is only under the action of pressure and not controlled by tensile stress,when the vertical pressure is equal to zero,the support will temporarily lift off,and the aspect ratio of the superstructure and the magnitude of the vertical earthquake peak acceleration will have an impact on this phenomenon.In previous studies,the value of vertical earthquake peak acceleration was conservative.In this paper,we will use the finite element analysis software SAP2000 to build different models,input different magnitudes of vertical earthquake peak acceleration,and perform time history analysis.And for the friction pendulum pilot project in which the research team participated in the construction,the relevant procedures and requirements in the installation and construction of the bearing were proposed,and a structural health monitoring plan was initially formulated.The main research contents and conclusions of this article are as follows:(1)A sufficient equivalent condition for the overturning state of a friction pendulum isolated structure is proposed.(2)Models of friction pendulum isolated structures with different height-to-width ratios are established,and their time-history analysis is performed to compare with non-isolated structures.With the increase of the aspect ratio,the self-vibration period extension coefficient decreases,the inter-layer shear force ratio increases,the anti-overturning ratio decreases,the number of bearings with lift-off phenomenon increases,and the maximum lift-off height increases.When the height and width are relatively large,the influence of high-order mode shapes on the structure should be considered.(3)Establish a friction pendulum pilot engineering model in which the research team participates in construction,and input vertical peak acceleration of differentmagnitudes to it.As the vertical acceleration of the vertical earthquake increases,the axial force on the column increases,and the maximum lift height of the support increases.The middle support is subjected to a large compressive stress.The supports that are lifted off are both the angle support and the side support,and the lift height of the angle support is higher than that of the side support.(4)This paper introduces the installation process of the friction pendulum vibration isolation support of the pilot project,the allowable range of installation deviation,how to control the deviation and the correction method,and installation quality acceptance.A set of structural health monitoring schemes for the pilot project were initially formulated,and their monitoring purposes,required instruments and equipment,and measurement point arrangements were introduced.