Experiment Based Seismic Behavior Investigation of a Sliding Controlled Isolation System

Abstract

The main objective of this study is to investigate the seismic behavior of an optimized version of cable-sliding friction aseismic bearing system, which is a spherical bearing combined with a set of cables to control the sliding. Basic characteristics and design method of this bearing are introduced. An experimental study including axial tensile tests of the cables and pseudostatic tests of the bearing are conducted. Seismic features including hysteretic loops, friction coefficient, and lateral restraining stiffness are analyzed based on the test data. After the test, the bearing is dissembled and damages to the bearing are illustrated and analyzed. A numerical simulation method is carried out and comparisons with the experimental results are made. The numerical results compare favorably with the experimental results. Furthermore, a case study featuring an extra-dosed cable-stayed bridge is presented. The experimental data confirm the effectiveness of the proposed design yet indicate degradation in the lateral restraining stiffness of the bearing. The case study results imply that the proposed system can control the relative displacement between the girder and pier effectively and momentary increase in the time history of the girder acceleration and pier top acceleration could be witnessed accompanying the restraining behavior. This study may be of use for seismic optimization of bridges in seismic active region.