一种可考虑形状效应的浅埋板锚极限抗拔力计算方法

一种可考虑形状效应的浅埋板锚极限抗拔力计算方

法

Introduction

Ingeotechnicalengineering,thestabilityofastructureiscrucialforensuringsafetyandfunctionality.Inmanycases,structuresareanchoredtothegroundusingplateanchorsinshallowdepths,whicharesubjectedtoupliftforcesduetowindsorsoilpressures.Thedesignofshallowplateanchorsrequiresconsiderationofvariousfactors,includingthedimensionsandshapeoftheanchor,thepropertiesofthesoil,andthemagnitudeoftheupliftforces.Inrecentyears,researchershaveemphasizedtheimportanceofconsideringtheshapeeffectoftheanchoronthelimitupliftcapacity.Thispaperaimstodiscussamethodforcalculatingthelimitupliftcapacityofshallowplateanchorsusingtheshapeeffect.

Background

Theperformanceofshallowplateanchorsisinfluencedbyvariousfactors,includingtheshapeoftheanchor,soilproperties,anchorsize,andloadingconditions.Mostpreviousstudiesontheupliftcapacityofshallowanchorshavefocusedontheeffectoftheanchorsizeandsoilproperties.However,recentstudieshavesuggestedthattheanchorshapecanalsoaffectthelimitupliftcapacity.Theshapeeffectarisesfromthefactthatdifferentshapesofanchorsproducedifferentfailuremechanismsandfailurezones,whichcansignificantlychangetheupliftcapacity.

Methods

Thelimitupliftcapacityofshallowplateanchorscanbecalculatedusingthefollowingformula:

Q=βuA

WhereQistheultimateupliftcapacityoftheanchor,βuistheupliftcapacitycoefficient,andAistheareaoftheanchor.Thecoefficientβuisusuallydeterminedthroughlaboratorytestingoranalyticalmethodsanddependsonthesoilproperties,anchorsize,andshape.Toaccountfortheshapeeffect,thecoefficientβucanbemodifiedtoincludeashapefactor,whichreflectsthecontributionofthe

anchor'sshapetotheupliftcapacity.Theshapefactorvarieswiththegeometryoftheanchorandcanbeobtainedthroughanalyticalornumericalmethods.

Oneapproachtoaccountingfortheshapeeffectistousethefiniteelementmethod(FEM)toanalyzethedeformationbehaviorandfailuremechanismoftheanchor.TheFEMcansimulatetheinteractionbetweentheanchorandthesoilandprovideinsightsintotheupliftcapacityoftheanchor.TheresultsfromtheFEManalysiscanbeusedtodeterminetheshapefactorandmodifytheupliftcapacitycoefficientβu.

Anotherapproachistouseempiricalequationstocalculatetheshapefactor.Severalresearchershaveproposedempiricalequationsthatrelatetheshapeoftheanchortotheupliftcapacity.Forexample,ChenandWang(2019)proposedanempiricalequationthataccountsfortheshapeeffectbasedontheanchor'saspectratioandeccentricity.Theequationisgivenas:

βu=β0+0.2(AR-1.5)+0.3e

Whereβ0isthecoefficientofacircularanchor,ARistheaspectratio,andeistheeccentricity.Theequationaccountsfortheshapefactorthroughtheterms(AR-1.5)ande,whichreflectthedeviationsoftheanchorfromacircularshape.

Discussion

Theshapeeffectonthelimitupliftcapacityofshallowplateanchorshasbeendemonstratedbyseveralresearchers.Theeffectarisesfromthedifferencesinfailuremechanismsandzonesfordifferentanchorshapes.Circularanchorstypicallyhaveauniformfailurezoneandcanachievehighupliftcapacities.However,non-circularanchors,suchasrectangularortriangularanchors,tendtohavenon-uniformfailurezonesandlowerupliftcapacities.Thesedifferencescanbeaccountedforusingtheshapefactor,whichdependsonthegeometryoftheanchor.

Thereareseverallimitationstothemethodsforcalculatingtheshapeeffectontheupliftcapacity.TheFEMapproachrequiresextensivecomputationalresourcesandexpertise,andmaynotbepracticalforroutinedesignapplications.Empiricalequationsmayhavelimitedapplicabilityandmaynotreflectthecomplexinteractionsbetweenthesoilandanchor.Therefore,furtherresearchisneededtodevelopmoreaccurateandpracticalmethodsforcalculatingtheshapeeffectonthelimitupliftcapacityofshallowplateanchors.

Conclusion

Theshapeeffectonthelimitupliftcapacityofshallowplateanchorsisanimportantconsiderationinthedesignoffoundationstructures.Theshapeeffectarisesfromthedifferencesinfailuremechanismsandzonesfordifferentanchorshapes.Theshapeeffectcanbeaccountedforusingtheshapefactor,whichdependsonthegeometryofthean