The　earth　pressure　of　backfill　behind　the　abutment　of　integral　abutment　jointless　bridge　(IAJB)　varies　substantially　as　the　bridge　girder　is　easily　subjected　to　load　due　to　cycling　temperature.　This　earth　pressure　that　increases　continuously　due　to　seasonal　variations　in　temperature,　results　in　the　actual　earth　pressure　of　the　backfill　is　much　larger　than　the　designed　earth　pressure,　and　the　accumulative　deformations　in　abutment　and　pile　emerge.　Therefore,　the　crucial　problems　with　IAJBs　include　effectively　reducing　the　earth　pressure　behind　the　abutment,　eliminating　the　accumulative　deformation,　and　reducing　the　horizontal　thrust　of　the　girder　under　temperature　load.　Based　on　the　specimens　of　abutment　H-shaped　steel　pile,　a　low-cyclic,　pseudo-static　experiment　was　carried　out　on　abutment　pile　soil　interactions　in　IAJBs　that　incorporate　expanded　polystyrenes　(EPS).　The　hysteresis　curves　and　their　skeletons　of　the　abutment　and　pile,　the　horizontal　deformations　along　the　depth　direction　of　the　soil,　and　the　angles　of　the　abutments　were　achieved.　The　influence　on　abutment-pile-soil　interaction　behavior　was　preliminarily　studied　by　different　thickness　of　EPS　fillers.　The　results　of　these　investigations　indicate　that　the　horizontal　thrust　on　the　abutment　due　to　girder　expansion　is　reduced　effectively　after　the　burial　of　the　EPS　fillers　behind　the　abutment.　Specifically,　the　thrust　reduces　31%　when　the　thickness　of　the　EPS　filling　is　15　cm.　The　accumulative　deformation　of　the　pile　and　abutment　decreases　as　the　thickness　of　the　EPS　filling　increases,　especially　at　the　depth　of　0.4　m　below　the　top　of　the　pile,　where　the　deformation　reduces　74.3%.　In　addition,　the　EPS　filling　behind　the　abutment　remarkably　reduces　the　constraints　on　the　rotation　angle　by　the　backfill.　Nevertheless,　the　deformations　under　a　single　step　of　displacement　loading　increase　by　a　small　amount　after　the　burial　of　the　EPS　fillers.　These　fillers　provide　adequate　elasticity　and　flexibility,　and　they　exhibit　reasonable　mechanical　properties　under　cycling　temperature　loads.　©　2019,　Editorial　Department　of　China　Journal　of　Highway　and　Transport.　All　right　reserved.