Offshore　turbines　are　often　supported　on　large-diameter　steel　pipe　monopoles.　There　is　a　significant　effect　of　soil-added-resistance　force　caused　by　the　rotation　of　the　pile　section　of　laterally　loaded　large-diameter　steel　pipe　piles.　The　impact　of　the　soil-added-resistance　force　on　pile　lateral　capacity　should　be　taken　into　account.　A　modified　Winkler　foundation　beam　model　was　proposed　to　model　the　lateral　bearing　loads　of　large-diameter　steel　pipe　piles,　in　which　the　soil　and　the　pile　are　respectively　modeled　by　nonlinear　springs　and　C1　beam　elements　considering　the　shear　deformation.　Assuming　that　the　secant　stiffness　of　the　soil　load　transfer　curves　inside　a　pile　element　is　linear,　finite　element　formulas　were　deduced　to　develop　a　coupling　method　which　can　take　into　account　the　soil-added-resistance　force　caused　by　the　rotation　of　the　pile　section,　and　a　corresponding　program　was　written.　Two　case　studies　were　performed　to　verify　the　coupling　method　developed　in　this　paper,　and　their　computed　results　were　compared　with　those　obtained　by　the　p-y　method　only　considering　the　lateral　nonlinear　springs＇　effect.　The　results　show　that　the　coupling　method　can　better　predict　the　laterally　loaded　characteristics　of　the　large-diameter　steel　pipe　pile.　The　closer　the　deformation　of　the　large-diameter　steel　monopile　is　to　the　rigid　rotation,　the　more　obvious　the　soil-added-resistance　force　caused　by　the　rotation　of　the　pile　section.　On　the　contrary,　the　soil-added-resistance　force　can　be　ignored　while　the　deformation　of　the　large-diameter　steel　pipe　pile　is　close　to　the　flexible　deformation.　©　2019,　Science　Press.　All　right　reserved.