Experimental Performance of Repaired Reinforced Concrete Hollow-Bridge piers

• Main Authors: Jyh-Csyang Yang, 楊智雄
• Other Authors: Chin-Tung Cheng
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/39660769970350058296

碩士 === 國立高雄第一科技大學 === 營建工程系 === 89 === Designed by the principle of weak column-strong beam, bridge piers are vulnerable following an earthquake. Failure of existing bridge columns such as longitudinal bar fracture, shear failure and bond loss of the lap splice are commonly seen. The objective of this research is to propose an effective repair technique for hollow bridge columns so that bridge function can be quickly restored after earthquakes. The repair aims to restore seismic capacity in terms of strength and ductility without changing above-mentioned design principle for bridges. To repair the longitudinal bar fracture in the plastic hinges, a newly designed dog-bone shape bars was applied. After replacing damaged concrete, various layers of FRP warp was applied for columns damaged due to flexure, shear failure and bond loss of the lap splice. The use of FRP is to provide lateral confinement or shear strength for the columns. Test result showed that column with flexural-shear deficiency was upgraded to flexural dominance after repair. In addition, its deformation capacity was enhanced 50% more; while ultimate strength was not restored as high as expected due to the concrete deterioration at cracks. For the column with longitudinal bar fracture, dog-bone bars plus FRP confinement successfully restored column strength up to 75% of original column. However, stiffness of repair columns was dramatically reduced due to ignore of flexural cracks beyond hinge zones. For column originally failed due to the bond loss, confinement of FRP at the lap splice region did not alter the failure mode due to a very short lap length. However, deformation capacity of column was greatly enhanced.