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: Thispaperdescribesthedesignandconstructionofbridgeapproachembankmentsconstructedonlooseliquefiablesoilsandcompressiblesoftground.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;

Please include this code when submitting a data update: GEO2014_102

Access this article:
Canadian Geotechnical Society members can access to this article, along with all other Canadian Geotechnical Conference proceedings, in the Member Area. Conference proceedings are also available in many libraries.

Cite this article: