Shaking table test and investigation of rocking effect in a high-rise isolated structure

Abstract

Laminated rubber bearings have a large compression stiffness and small tension stiffness and isolation layers show rocking deformation under bending moments. The application of isolation technology is limited in high-rise structures due to the unequal compression and tension stiffnesses. The rocking effect of a high-rise isolated structure was investigated in this work. To do this, a dynamic model of a high-rise isolated structure considering non-linear tension behaviour of the isolator and the stiffness centre offset was established. The limit criterion of the rocking angle and the corresponding input peak ground acceleration of the tension limit, damage limit and collapse limit were determined. A shaking table test of the isolated model was conducted and the aspect ratio was found to have a great influence on the structural rocking response. The response of the large aspect ratio (LAR) model was larger than that of a model with a small aspect ratio. The bearings in the LAR model were more likely to be tensioned. The test results and numerical simulations were close, confirming the accuracy of the proposed dynamic model and the limit criteria. Subsequently, dynamic analysis of frame–shear wall structures was conducted and the influence of aspect ratio and earthquake level was investigated. The proposed theories can be applied for direct predictions of rocking response and the performance state of isolators.