Dynamic model and shaking table tests for curved surface isolated structures

In recent years, strong earthquakes beyond initially estimated strength frequently take place, ordinary isolated structures have risks of excessive displacements of isolation layer, support sheared and even collisions between isolated structures and retaining walls under the action of beyond-designed earthquakes. Here, a new curved surface isolated structure system with curved surface characteristics of isolation layer and structural gravity effect was proposed to control isolation layer's displacement responses of the system under strong earthquakes. A simplified single mass point analysis model for the proposed structure was built with tilted isolated bearings to theoretically analyze the system's acceleration transfer coefficient and displacement one. Finally, a five-story steel frame model with a curved surface isolated structure was designed and made. Shaking table tests were conducted for this model, a planar isolated structure model and a non-isolated structure one, respectively. The test results showed that the acceleration response of the curved surface isolated structure model is larger than that of the planar isolated structure one, but much smaller than that of the non-isolated structure one; its isolation layer displacement obviously is smaller than that of the planar isolated structure one; the test results agree well with those of theoretical study. © 2019, Editorial Office of Journal of Vibration and Shock. All right reserved.