A　reciprocating　low-cycle　pseudostatic　loading　test　on　four　prestress　high-strength　concrete　(PHC)　pipe　piles　was　performed　to　study　their　failure　modes　and　seismic　behaviors.　The　distributions　of　lateral　deformation　and　soil　pressure　along　the　piles　as　well　as　their　analysis　methods　were　studied.　The　test　results　show　that　with　an　increase　in　the　embedded　depth　of　pile,　the　soil　pressure　around　the　piles　initially　increased　up　to　the　maximum　and　then　decreased　or　even　reversed　slightly　at　a　certain　depth.　The　pressure　at　shallower　soil　increased　rapidly,　up　to　nearly　the　ultimate　passive　earth　pressure,　while　the　pressure　at　the　deeper　soil　increased　relatively　slowly.　The　results　further　indicate　that　the　strain　transformation　method　and　m　method　were　only　appropriate　for　calculating　the　lateral　displacements　of　piles　under　linear　and　small　deformation　but　not　suitable　to　calculate　lateral　displacement　of　piles　under　large　deformation.　Moreover,　although　the　p-y　curve　method　took　into　account　the　nonlinearity　of　soil,　the　calculated　lateral　displacement　and　soil　pressure　of　pile　still　showed　a　significant　difference　with　the　test　results,　especially　under　large　deformation.　Furthermore,　modified　calculations　of　lateral　displacement　and　soil　pressure　of　pile　were　proposed　based　on　regression　analysis　on　the　test　results　and　existing　p-y　curve　methods,　respectively,　and　calculated　results　showed　a　good　agreement　with　the　test　results　in　terms　of　lateral　displacements　and　soil　pressures.　Therefore,　they　were　recommended　for　analyzing　the　soil-pile　interaction　for　pile　foundations　in　integral　abutments　jointless　bridges　(IAJBs).