The　seismic　resilience　of　steel　bridge　piers　can　be　weakened　due　to　the　ageing　effect　that　occurs　throughout　their　entire　life-cycle　stage.　Seismic　strengthening　is　a　practical　approach　to　enhance　the　seismic　performance　of　ageing　piers.　Nevertheless,　the　conventional　strengthening　methods　often　result　in　a　higher　stiffness　of　bridge　piers.　This　can　potentially　intensify　the　local　seismic　responses　of　the　strengthened　bridge　pier　and　change　the　failure　mode　during　seismic　events.　Hence,　this　study　extends　a　strengthening　technique,　the　Contact　Stiffener　Strengthening　Method　(CSSM),　which　aims　to　enhance　the　ductility　of　ageing　steel　bridge　piers　without　causing　an　excessive　increase　in　stiffness.　This　method　uses　the　contact　effect　to　increase　the　seismic　performance　of　aging　piers　by　ingeniously　designed　stiffeners.　The　static　and　dynamic　approaches　are　employed　to　compare　the　effects　of　CSSM　and　traditional　strengthening　methods　on　seismic　performance　enhancement.　Finally,　this　study　proposes　the　prediction　methods　for　the　ultimate　strength　and　displacement　of　the　strengthened　piers.　The　analysis　results　reveal　that　the　occurrence　of　the　contact　phenomenon　and　buckling　at　the　free-end　plate　indicate　the　initiation　and　ultimate　states　of　the　contact　stiffeners.　The　strengthening　efficiency　in　retrofitted　piers　is　greatly　influenced　by　the　parameters　of　the　free-end　plate.　The　strengthening　efficiency　of　bridge　piers　can　be　significantly　affected　by　varying　parameters　of　corrosion　when　using　the　same　contact　stiffener.　The　errors　in　the　proposed　prediction　methods　for　the　ultimate　displacement　and　ultimate　strength　of　the　strengthened　piers　can　be　controlled　within　15%　and　10%,　respectively.　©　The　Author(s),　under　exclusive　licence　to　Springer　Nature　B.V.　2024.