The　accuracy　of　concrete　lateral　pressure　predictions　affects　the　safety　and　economic　aspects　of　constructions.　For　the　prediction　of　the　maximum　lateral　pressure　of　bottom-up　pumping　self-compacting　concrete,　based　on　the　graph　multiplication　method,　a　calculation　model　with　time-varying　coefficients　was　proposed,　which　considers　the　friction　effect.　The　time-varying　characteristics　of　the　key　coefficients　of　self-compacting　concrete　with　slumps　of　600　mm,　700　mm,　and　800　mm　were　studied　by　simulating　the　concrete　pouring　process　and,　then,　applied　to　the　calculation　model.　In　two　dumbbell-shaped　steel　arch　bridges,　pressure　sensors　were　placed　in　the　inner　wall　of　the　typical　steel　pipe＇s　section　to　measure　the　lateral　pressure　during　the　pumping　process　and,　hence,　verify　the　accuracy　of　the　calculation　model.　The　applicability　of　the　calculation　model　was　verified　by　comparing　the　calculated　results　with　other　specifications.　Results　indicate　that,　as　the　liquid　level　increases,　the　effect　of　friction　will　cause　a　significant　increase　of　pressure　at　the　bottom.　In　predicting　the　maximum　lateral　pressure　of　bottom-up　pumping　self-compacting　concrete,　the　calculation　model　can　be　well　applied　in　the　case　where　the　liquid　level　was　higher.