傳統滑動隔震支承已被廣泛應用，且具有相當良好之隔震效果，但易與近斷層產生低頻共振現象，減低其隔震效能。前人研究具變頻特性之隔震支承可有效改善傳統隔震支承於近斷層地震之隔震效果，但仍有支承摩擦材選用不易的問題。本文採用多項式滾動隔震支承(Polynomial Rocking Bearing, PRB)，PRB隔震支承之滾動曲面為六次多項式構成，具變頻特性，其遲滯迴圈有軟化段及硬化段之不同隔震效果，軟化段可降低結構物加速度反應，硬化段可抑制支承鉅大位移量，此外，改變PRB幾何性質亦可輕易調整其等效水平摩擦係數，因此摩擦材可任意選擇，增加支承之可靠度及耐用度。 根據前人研究已證實PRB對建築結構具有良好之隔震效果，尚未有應用於橋梁之實例。本研究以實驗結果驗證PRB理論與數值分析之正確性，依據日本道路橋示方書建立一座橋梁模型，使用PSO-SA混和搜尋法求得PRB支承最佳設計參數，並比較傳統摩擦單擺支承(Friction Pendulum System, FPS)與PRB之隔震效益。 Conventional sliding isolators are widely used and effective to reduce seismic hazard, but it may not be effective when the structures are subjected to near-field ground motions because the pulse periods ground motions are usually close to the isolation periods of the isolators, and it may lead isolated structures to resonate with the ground motions. Various frequency sliding isolators could improve the performance of seismic isolation under near-field ground motions, but chosen friction materials were a difficult issue. In this study is using Polynomial Rocking Bearing (PRB). The rocking surface of PRB consists of six-order polynomial. The restoring stiffness possesses two sections: softening section and hardening section. The structural acceleration response can be reduced by decreasing the restoring stiffness, while the structural displacement response can be reduced by increasing the restoring stiffness of PRB. PRB equivalent horizontal friction coefficient can be easily adjusted via the bearing geometry, so the friction material can be arbitrarily chosen, increasing the isolator reliability and durability. According to previous studies the PRB effective to reduce seismic hazard on building structure, but it is not yet used in the bridges. In this study, PRB experimental results verify the accuracy of theoretical and numerical analysis. Find out the optimal parameters of PRB by using PSO-SA hybrid algorithm, and compare the isolation effectiveness between PRB and Friction Pendulum System (FPS).
