Osterberg Cell Pile Load Test in Calgary, Alberta - A Case Study

Deepak Kumar, Joseph Yonan, A.F. Ruban

Dans les comptes rendus d’articles de la conférence: GeoRegina 2014: 67th Canadian Geotechnical Conference

Session: Earth Walls and Foundations

ABSTRACT: ThelocalgeologyofthenorthwestareaofCalgarywithintheouterBowRiverValleygenerallyincludesthepresenceoflacustrinesoilsoverlyingglacialtill.Theconsistencyofthelacustrinesoilinthisareaisfrequentlysofttofirmandisaccompaniedbyshallowgroundwateratsomelocations.Thethicknessofthelacustrinesoilsvariesinthisareaandposesfoundationchallenges,particularlywherehighstructuralloadsareanticipated.Accurateestimatesoffoundationdesignparametersinthesesoilscanhavesignificantimpactontheconstructioncostandperformanceoffoundations.Withtheseconsiderations,apileloadtestonaboredcast-in-placebelledpile,drilledthroughthelacustrinesoilsandbasedinglacialtillwasconducted,utilizinganOsterbergCell(O-Cell)method.ThetestwasconductedforTradesandTechnologyComplexdevelopmentofSouthernAlbertaInstituteofTechnology,locatedinnorthwestCalgary,Alberta.Thispaperpresentsacasehistoryofthepileloadtestanddiscussionofthefindingsofthepileloadtest.RÉSUMÉLagéologielocaledunord-ouestdeCalgarysetrouvantsurleborddelavalléedelarivièreduBowcomprendlaprésencedessolslacustrepar-dessusunecouchedetillglaciaire.Lacohérencedusollacustresdanscedomaineestsouventsoupleàfermeetestaccompagnéd'eauxsouterrainespeuprofondesàcertainsendroits.L™épaisseurdecessolsvariesdanscetterégionetposesdesdifficultéspourdesfondations,notammentpourceuxavecdeschargesdestructureélevés.Desestimationsprécisespourdesparamètresdeconceptiondebasedanscessolspeuventavoiruneffetsignifiantsurlescoûtsdeconstructionetlaperformancedesfondations.Enprenantcomptedeceseffets,untestdechargedepileaétémiseenplaceparforersurplaceenformedeclocheunpilierdanslessolslacustreetbasésdansletillglaciaire,enutilisantlemodèleOsterberg(O-cell).Cetestaétéconduitpouruneadditionpourl™institutdetechnologiedel™AlbertaduSud(SouthernAlbertaInstituteofTechnology),setrouvantdanslenord-ouestdeCalgary.Cetravailprésenteunepréhistoiredecetestdechargementdespiliersetlesdiscussionsdecesrésultats.1INTRODUCTIONPileloadtestsaregenerallyconductedtobetterestimatethepiledesignparameters,optimizetheprojectcost,ortobeabletousehigherresistancefactorsinthelimitstatesdesignmethodology.TheCanadianFoundationEngineeringManualallowstheuseofahigherresistancefactorwhendesignparametersareestimatedusingloadtestresults.WithanOsterbergcell(O-Cell),pileloadtestondeeppilescanbeconductedeconomically,comparedtotheconventionaltestingmethod.Theconventionalmethodgenerallyrequirestheuseofreactionpiles,whicharenotneededwhenusinganO-Cellmethod.GiventhattheO-CellutilizesreactionfromshaftfrictionabovetheO-CellandfromendbearingandshaftresistancesbelowtheO-Cell,testingashorterpileusingO-Cellmightnotprovideallthedesireddesignparameters.ThispaperpresentsacasestudyofapileloadtestthatwasconductedusinganO-CellatSouthernAlbertaInstituteofTechnology(SAIT)inCalgary,Alberta.Piledesignparametersestimatedfromtheloadtesthavealsobeencomparedwiththoseestimatedfromanalyticalorempiricalmethods.2BACKGROUNDThisloadtestwasconductedduringthefoundationdesignoftheTradesandTechnologyComplexwithinSAITcampusinnorthwestCalgary,Alberta(Figure1).Theentireprojectinvolvedconstructionofthreenewbuildingstructureswithpartialtofullbasements.Columnswithfactoredloadsofupto13,200kNweretobesupportedonpilefoundations.Intotal,theprojectinvolvedinstallationofmorethan400boredcast-in-placeconcretepiles.Consideringthenumberofpilesandtheirdesignloads,onepileloadtestwasconductedtoobtainamoreaccurateestimateofpiledesignparametersaswellastobeabletoutilizeahigherresistancefactorforpiledesign.

Please include this code when submitting a data update: GEO2014_105

Retrouver cet article:
Les membres de la Société canadienne de géotechnique peuvent accéder à cet article, ainsi qu'à tous les autres articles de la Conférence Géotechnique Canadienne, dans le Espace membre. Les comptes rendus d'articles sont également disponibles dans de nombreuses bibliothèques.

Citer cet article: