RESIDUAL STRENGTH OF DAMAGED STEEL BRIDGE PIER WITH CIRCULAR CROSS SECTION AND ITS REPAIR METHOD

After HYOGOKEN-NANBU Earthquake in 1995 at Kobe，Ja pan，many researches for seismic resistance design have become actively. Especially seismic resistance design researches of steel bridge piers tend to how to strengthen them to against to severe earthquakes. For example，researches of improving the strength and the ductility by strengthen the cross section and proportion or by applying high performance materials，such as low yield steel，and so on. But，most of the above researches are only for new bridge piers or constructed by old design codes，and these piers are not experienced severe damages caused by earthquakes. Therefore there is no guideline about repairng methods for damaged steel bridge piers. And there is no assessment techniques retrofitted piers are established until now. In this study，firstly，we introduce repairing methods for local buckled of steel bridge piers after cyclic loading experiments. We prepared 6 damaged steel pier specimens，which had elephant foot bulge buckling at the bottom of pier，and repair them by filling concrete inside. After repairing，perform cyclic loading experiments are conducted under same load sequence，and by comparing the seismic resistance capacity between before and after repaired to discuss the reliability of repairing methods