setotunnellingisunderstoodtheoreticallybytheconvergence-confinementmethod,whichconsistsofthreeelements:longitudinaldeformationprofile,groundreactioncurve,andsupportcharacteristiccurve.Theseepageforcesarelikelytohaveastronginfluenceonthegroundreactioncurvewhichisdefinedastherelationshipbetweeninternalpressureandradialdisplacementofthetunnelwall.Inthispaper,seepageforcesarisingfromthegroundwaterflowintoatunnelwereestimatedquantitatively.Magnitudeofseepageforceswasdeterminedbasedonhydraulicgradientdistributionaroundtunnel.Toestimateseepageforces,differentcoverdepthsandgroundwatertablelevelswereconsidered.Usingtheseresults,thetheoreticalsolutionsforthegroundreactioncurve(GRC)withconsiderationofseepageforcesundersteady-stateflowwerederived.INTRODUCTIONWhenatunnelisexcavatedbelowthegroundwatertable,groundwatermayflowintothetunneland,consequently,seepageforcesmaydevelopinthegroundseriouslya