Ground improvement for a bridge approach embankment - a case history

Uthaya M. Uthayakumar, Ujjal Chakraborty

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

Session: Infrastructure

ABSTRACT: ovementforabridgeapproachembankmentŒacasehistory(Uthaya)M.UthayakumarTetraTechEBA,Vancouver,BC,CanadaUjjalChakrabortyExpServicesInc.,Burnaby,BC,CanadaABSTRACTThispaperdescribesthedesignandconstructionofbridgeapproachembankmentsconstructedonlooseliquefiablesoilsandcompressiblesoftground.Theprojectincludeddesignandconstructionofafive-lanebridgeoveranexistinghighway,twofour-lanebridgesoveracreek,approachembankments,anat-gradecrossingoveranexistingrailwaylineandconstructionofMSEretainingwalls.TheapproachembankmentfillsareretainedusingMSEwalls.Threedifferentgroundimprovementmethodswereutilizedinthisproject.Settlementmonitoringwascarriedoutduringconstructionandoveraperiodoftwoyearsfollowingcompletionofconstruction.Anoverviewofthesubsurfacesoilandgroundwaterconditions,geotechnicaldesignoftheapproachembankments,descriptionofgroundimprovementmethodsusedandtheresultsofsettlementmonitoringarepresented.RÉSUMÉCepapierdécritlaconceptionetlaconstructiondebergesd'approchedepontconstruitessurdesterrainsmeublesetsurunsolcompressiblemou.Leprojetcomprenaitlaconceptionetlaconstructiond'unpontàcinqvoiessuruneautorouteexistante,dedeuxpontsàquatrevoiesau-dessusd'unruisseau,debergesd'approche,d'uncroisementausolavecunelignedechemindeferexistanteetlaconstructiondemursdesoutènementMSE.Lesremblaisdelaberged'approchesontconservésenutilisantdesmursMSE.Troisméthodesd'améliorationdesoldifférentesontétéutilisésdanslecadredeceprojet.Lesuividutassementaétéeffectuéaucoursdelaconstructionetsurunepériodededeuxanssuivantl'achèvementdelaconstruction.Unexposédesconditionsdusous-soletdeseauxsouterraines,delaconceptiongéotechniquedesbergesd'approche,deladescriptiondesméthodesd'améliorationdusoletdesrésultatsdusuividutassementsontprésentées.1INTRODUCTIONThiscasehistorydescribesapartoftheEvansRoadConnectorproject,locatedinChilliwack,BritishColumbia.Theprojectincludedthedesignandconstructionofthefollowingelements:afive-lanebridgeovertheexistingLuckakuckWayandTrans-CanadaHighway(TCH);aneastboundoff-rampandawestboundon-rampaccesstotheTCH;afour-lanebridgeoverChilliwackCreek;anotherfour-lanebridgeoverChilliwackCreekDiversion;MSEretainingwallsand;anat-gradecrossingovertheexistingCNRailwaytracks.ThispaperpresentstheworkcompletedforthebridgestructureovertheTCH.Figure1showsthelocationoftheentireprojectsite.ThesubsurfacesoilsatthesiteconsistofFraserRiversediments,whichincludecompressiblesilts,followedbysiltysandorsandandgravelwithoccasionalsandysiltlayers,extendingtoupto60mdepth.Geotechnicalconsiderationsoftheprojectincludethedesignoffoundationsforthebridgestructures,settlementanalysisofthefoundationsandtheapproachembankments,seismicdesignofthefoundationsandtheembankments,staticandseismicslopestabilityoftheapproachembankments,designoftheMechanicallyStabilizedEarth(MSE)retainingwalls,liquefactionassessmentofthesubsurfacesoils,assessmentoftheconsequencesofliquefactionandthedesignofremedialmeasures.Figure1.Locationoftheprojectsite(ModifiedfromGoogleearth)Groundimprovementmethodsutilizedforthisprojectincludethefollowing:excavationofthenear-surfacecompressiblesoilsandreplacementwithgranularfill;grounddensificationusingvibro-replacementstonecolumnmethodtomitigateliquefactionpotentialofgranularsoils,and;

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Cite this article:
Uthaya M. Uthayakumar; Ujjal Chakraborty (2014) Ground improvement for a bridge approach embankment - a case history in GEO2014. Ottawa, Ontario: Canadian Geotechnical Society.

@article{GeoRegina14Paper102,author = Uthaya M. Uthayakumar; Ujjal Chakraborty,title = Ground improvement for a bridge approach embankment - a case history,year = 2014}