fiedasradiallossaroundthetunnelperipheryandaxial(face)lossattheexcavationface(Attewelletal.;Schmidt).Theexactratioofradialandaxialvolumelossesisnotfullydemonstratedorgeneralizedinanystudy.However,itispossibletodiminishorminimizethefacelossinfull-facemechanizedexcavationsbyapplyingafacepressureasaslurryofbentonite–watermixtureorfoam-processedmuck.Thegroundlossisusuallymoreingranularsoilsthanincohesivesoilsforsimilarconstructionconditions.Thewidthofthesettlementtroughonbothsidesofthetunnelaxisiswiderinthecaseofcohesivesoils,whichmeanslowermaximumsettlementforthesameamountofgroundloss.Timedependencyofgroundbehaviorandexistenceofundergroundwaterdistinguishshort-andlong-termsettlements(Attewelletal.).Short-termsettlementsoccurduringorafterafewdays(mostlyafewweeks)ofexcavation,assumingthatundrainedsoilconditionsaredominant.Long-termsettlementsaremostlyduetocreep,stressredistributionandconsolidationofsSmax值单隧道和双隧道模型分别如试和所示(throughArioglu):