PredictionofradialstressesduetoprestressinginPSCshellsOriginalResearchArticle

Largeprestressedconcrete(PSC)shells,suchassilos,containmentstructuresareprestressedalongtheirprincipalcurvatures.Prestressingcablesareprovidedinthethicknessoftheshelleitherinoneortwodirections.Thestressesnormaltothemiddlesurfacearegenerallyneglectedinthedesignofsuchshellstructures.However,thedevelopmentofradialtensilestressesatthetimeofprestressingcanleadtopossibledelaminationfailure,ifthesestressesareexcessive.Thispaperpresentssimpleprocedurestoestimatetheradialstressdistributionduetoprestressing.Twomethodsarepresented:‘equilibriumofslice’and‘modifiedLamé,’thelatterbeingmorerigorousandapplicabletobothsinglyanddoublycurvedshells.Thesolutionsobtainedareinconformitywiththeresultsoffiniteelementanalysispublishedearlier.Finally,anattemptismadetodeterminethelocaltensilestressdistributionattheperipheryoftheprestressingducthole,whichalsocontributedtotheproblemofdelamination.