To　analyze　the　effect　of　horizontal　reciprocating　large　displacement　generated　by　the　abutment　on　the　interaction　between　the　abutment　and　the　backfill　behind　the　abutment　under　the　actions　of　strong　earthquake　and　temperature,　a　quasi-static　test　for　the　interaction　among　the　integral　abutment,　H-shaped　steel　pile,　and　soil　was　carried　out.　On　the　basis　of　the　test　results,　the　distribution　law　of　the　earth　pressure　behind　the　integral　abutment　under　the　action　of　large　displacement　was　studied.　According　to　the　distribution　of　the　earth　pressure　behind　the　abutment,　the　relational　expression　between　the　action　point　location　of　the　resultant　earth　pressure　behind　the　abutment　and　the　loading　displacement　was　proposed,　and　an　improved　calculation　method　for　the　earth　pressure　behind　the　integral　abutment　was　given　based　on　the　existing　research.　Research　results　indicate　that　when　the　abutment　is　loaded　in　the　positive　direction　(the　abutment　squeezes　the　soil　behind　the　abutment),　the　earth　pressure　behind　the　abutment　first　increases　and　then　decreases　as　the　loading　displacement　rises.　Earth　pressures　at　the　abutment　back　and　20%　of　the　abutment　height　behind　the　abutment　are　highly　affected　by　the　abutment　displacement　and　has　a　trapezoidal　distribution　along　the　depth　direction.　In　the　earth　pressure　distribution　at　the　abutment　back,　due　to　the　constraint　of　H-shaped　steel　pile　at　the　bottom　of　the　abutment,　the　maximum　earth　pressure　is　located　at　a　depth　of　0.875　m,　and　the　earth　pressure　at　the　bottom　of　the　abutment　decreases　slightly.　Earth　pressures　at　60%　of　the　abutment　height　and　1.4　times　the　abutment　height　behind　the　abutment　are　less　affected　by　the　abutment　displacement　and　is　triangularly　distributed　along　the　depth　direction.　When　the　abutment　is　loaded　in　the　negative　direction　(the　abutment　deviates　from　the　soil　behind　the　abutment),　the　earth　pressure　behind　the　abutment　is　triangularly　distributed　along　the　depth　direction,　and　the　earth　pressure　behind　the　abutment　has　no　connection　with　the　loading　displacement,　and　its　value　can　be　neglected　relative　to　the　positive　loading.　Under　the　action　of　a　horizontal　reciprocating　large　displacement,　the　soil　behind　the　integral　abutment　will　face　a　void　phenomenon,　and　the　void　range　will　exceed　37.5%　of　the　abutment　height.　The　earth　pressure　behind　the　abutment　reduces　exponentially　along　the　longitudinal　direction,　and　it　reduces　faster　than　that　under　the　action　of　a　small　displacement.　The　action　point　location　of　the　resultant　earth　pressure　behind　the　abutment　decreases　gradually　as　the　loading　displacement　increases,　and　the　earth　pressure　coefficient　behind　the　abutment　has　an　obvious　nonlinear　relationship　with　the　loading　displacement,　which　is　reflected　by　the　law　of　first　increasing　and　then　decreasing.　Existing　earth　pressure　calculation　methods　do　not　take　into　account　the　effect　of　the　abutment　displacement　or　consider　that　the　earth　pressure　behind　the　abutment　rises　with　the　increase　in　the　abutment　displacement　when　small　displacements　occur　and　remains　basically　unchanged　when　large　displacements　occur.　The　determination　coefficient　of　the　proposed　earth　pressure　fitting　formula　is　0.92,　and　the　relative　error　between　the　calculated　value　and　the　test　value　is　6.2%,　which　can　be　a　useful　supplement　to　the　existing　earth　pressure　calculation　methods.　©　2022　Chang＇an　University.　All　rights　reserved.