HIGH SEISMIC PERFORMANCE CONCEPT OF INTEGRATED BRIDGE PIER WITH TRIPLE RC COLUMNS ACCOMPANIED BY FRICTION DAMPER PLUS GAP

After the 1995 Kobe earthquake, the structural performance concept of a bridge in Japan considers two levels of seismic excitation which are named as Level 1 and Level 2. However, the Level 2 of ground motion input is a large seismic coefficient demand. Also, the problem of bridge rubber bearing support which commonly is used in Japan lost expected seismic performance due to the deterioration. Some possible causes of the deterioration are the aging, the compression fatigue, or the frequent lateral deformation which triggered by traffic load, wind load, thermal expansion, creeps, and shrinkages phenomena of daily load. While the behavior and the parameters of reinforced concrete (RC) column accompanied with friction device were determined successfully based on the experiment and numerical analysis. This study proposed the structural system of integrated bridge pier with triple RC column connected by friction damper plus gap which is expected to substitute the conventional bridge pier system avoiding the use of rubber bearing. In the investigation of its behavior and seismic performance, numerical analysis was performed with fiber cross-section of non-linear beam-column-based element model on the longitudinal direction of the bridge structure. As the analysis result, the proposed structure had an excellent performance not only under small deformation to allocate frequent lateral deformation but also under seismic load. Furthermore, in the structural simulations, the consideration of different limit state of column location and the various yield strength of reinforcing steel configuration can obtain a better structural cost-performance option