Experimental and Numerical Verification of a Sloped Sliding-Type Isolation Bearing

• Main Authors: Chih-Kuan Lin, 林致寬
• Other Authors: 鍾立來
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/s7bqra

碩士 === 國立臺灣大學 === 土木工程學研究所 === 105 === Isolation system is an effective way to reduce the earthquake load transmits to superstructure. In addition, sliding isolation bearing is one of the most commonly used isolation systems. The research on a conventional sliding isolation bearing, Friction Pendulum System (FPS), is known thoroughly nowadays. FPS possesses a specific isolation period due to the linear relationship between the restoring force and the isolation displacement. However, more studies have shown that FPS will be ineffective when the earthquake frequency approaches the isolation frequency, which may cause a resonant phenomonen. Therefore, the development of isolation technique has gradually focused on nonlinear isolation system these years. This article will introduce a new nonlinear isolation technique, Sloped Sliding-Type Bearing (SSB), which has a sloped sliding surface and the energy dissipation mechanism is mainly provided by the frictional force. Different from the design procedures of Lead Rubber Bearing (LRB) and FPS, the maximum base shear of SSB can be easily determined without iteration procedures when the two system parameters of SSB, friction coefficient and inclination angle, are decided. Besides, due to the nonlinearity between the restoring force and the isolation displacement of SSB, it does not possess a specific isolation period, which will be able to prevent the resonant phenomonen. This article will first derive the system’s equation of motion and arrange the simulation method. By a parametric study, the sensitivity of the system response toward the system parameters is able to comprehend. Furthermore, the system is proved that it does not possess a specific isolation period, and the absolute acceleration response is insensitive to the amplitude and frequency content of the earthquake. Due to not having a design procedure for SSB, a simple design method is proposed to determine the design parameters. By comparing SSB with FPS using a real isolated structure, SSB is shown to be effective under both far-field and near fault earthquake. Besides, it will show a better result than FPS under the near fault earthquake. Finally, by comparing the simulation results with the shaking table experiment results, the feasibility of SSB is verified and the simulation method is proved to be valid in order to present the dynamic behavior of SSB.