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

Deepak Kumar, Joseph Yonan, A.F. Ruban

In the proceedings of: GeoRegina 2014: 67th Canadian Geotechnical Conference

Session: Earth Walls and Foundations

ABSTRACT: ellPileLoadTestinCalgary,AlbertaŒACaseStudyDeepakKumar,M.Sc.,P.Eng.,JosephYonan,Ph.D.,P.Eng.,&A.F.Ruban,M.Eng.,P.Eng.TetraTechEBAInc.,Calgary,Alberta,CanadaABSTRACTThelocalgeologyofthenorthwestareaofCalgarywithintheouterBowRiverValleygenerallyincludesthepresenceoflacustrinesoilsoverlyingglacialtill.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.

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Cite this article:
Deepak Kumar; Joseph Yonan; A.F. Ruban (2014) Osterberg Cell Pile Load Test in Calgary, Alberta - A Case Study in GEO2014. Ottawa, Ontario: Canadian Geotechnical Society.

@article{GeoRegina14Paper105,author = Deepak Kumar; Joseph Yonan; A.F. Ruban,title = Osterberg Cell Pile Load Test in Calgary, Alberta - A Case Study,year = 2014}