北京軌道交通新機(jī)場線地面沉降特征及影響因素分析摘要：

近年來，北京市軌道交通發(fā)展迅速，新建的北京大興國際機(jī)場線也是其中之一。然而，隨著地面的機(jī)動車輛、建筑物和地下管道等工程的不斷增多，軌道交通施工和運(yùn)營引起了地面沉降的問題。本文以北京軌道交通新機(jī)場線為研究對象，對其地面沉降的特征及影響因素進(jìn)行分析。

首先，對新機(jī)場線地面沉降時(shí)間、空間分布特征進(jìn)行了分析，得出了機(jī)場線周邊地面沉降較為嚴(yán)重的結(jié)論。然后，探究了不同施工階段對地面沉降的影響及作用機(jī)理。結(jié)果表明，新機(jī)場線近期施工對周邊地面沉降影響最大。接著，根據(jù)多方因素影響，結(jié)合實(shí)際監(jiān)測數(shù)據(jù)，探究了地下建筑物、土壤物理性質(zhì)和基坑土方開挖等因素對新機(jī)場線地面沉降的影響因素。最后，針對影響因素，提出了相應(yīng)的治理措施和建設(shè)建議，為新機(jī)場線的安全穩(wěn)定運(yùn)營提供保障。

關(guān)鍵詞：北京軌道交通、新機(jī)場線、地面沉降、影響因素、施工階段、建設(shè)建議

Abstract：

Inrecentyears,thedevelopmentofBeijing'srailtransithasbeenrapid,andthenewlyconstructedBeijingDaxingInternationalAirportLineisalsooneofthem.However,withtheincreasingnumberofmotorvehicles,buildings,andundergroundpipelinesontheground,theconstructionandoperationofrailtransithavecausedtheproblemofgroundsubsidence.ThisarticletakestheBeijingRailTransitNewAirportLineastheresearchobjectandanalyzesthecharacteristicsandinfluencingfactorsofitsgroundsubsidence.

Firstly,thetimeandspatialdistributioncharacteristicsofgroundsubsidenceofthenewairportlinewereanalyzed,andtheconclusionthatthegroundsubsidencearoundtheairportlinewasmoreseriouswasdrawn.Then,theinfluenceandmechanismofdifferentconstructionstagesongroundsubsidencewereexplored.Theresultsshowedthattherecentconstructionofthenewairportlinehadthegreatestimpactonthesubsidenceofthesurroundingground.Next,basedontheinfluenceofmultiplefactorsandcombinedwithactualmonitoringdata,thefactorsaffectinggroundsubsidenceofthenewairportline,suchasundergroundbuildings,soilphysicalproperties,andexcavationoffoundationpits,wereexplored.Finally,correspondinggovernancemeasuresandconstructionrecommendationswereproposedfortheinfluencingfactorstoprovideguaranteeforthesafeandstableoperationofthenewairportline.

Keywords:BeijingRailTransit,NewAirportLine,GroundSubsidence,InfluencingFactors,ConstructionStage,ConstructionRecommendationIntroduction

TheNewAirportLineofBeijingRailTransit,asoneofthemajorprojectsinthecity,connectstheBeijingDaxingInternationalAirportandthedowntownareaofBeijing.Withtheincreasingdemandforairtravelandtheexpansionoftheairport,theconstructionofthenewairportlinehasbroughtgreatconveniencefortransportationandtourism.However,theconstructionofthenewairportlineisfacingsignificantchallengesingroundsubsidenceduetothecomplexgeologicalandhydrogeologicalconditionsinBeijing.Therefore,itisessentialtounderstandtheinfluencingfactorsandgovernancemeasuresofgroundsubsidenceduringtheconstructionstagetoensurethesafeandstableoperationofthenewairportline.

InfluencingFactorsofGroundSubsidence

UndergroundBuildings

Beijingisacitywithadenseundergroundbuildingnetwork,suchassubwaytunnels,utilitytunnels,andbasements.Theconstructionofthenewairportlinewillinteractwiththeseexistingundergroundbuildings,whichcancausegroundsubsidence.Forexample,themetroline7andtheutilitytunnelbetweenBeijingWestRailwayStationandtheSouthSecondRingRoadintersectwiththenewairportline.Therefore,itisnecessarytocompletethedisplacementandsettlementpredictionofthenewairportlineandthesurroundingundergroundbuildingstoensurethesafetyoftheundergroundspace.

SoilPhysicalProperties

Thesoilphysicalproperties,suchassoilpermeability,compressibility,andsettlementcharacteristics,arecriticalfactorsaffectinggroundsubsidence.Toconstructthenewairportline,alarge-scaleexcavationisneededtoexcavatethefoundationpitandinstalltheconstructionequipment.Theexcavationcanchangethesoilphysicalproperties,whichmayresultingroundsubsidence.Therefore,itisnecessarytoconductcomprehensiveandsystematicresearchonthesoilphysicalpropertiesoftheconstructionsitetounderstandthedegreeofsoildeformationcausedbyexcavationactivities.

ExcavationofFoundationPits

Theexcavationoffoundationpitsforthenewairportlineisacomplexprocessthatinvolvestheinteractionbetweentheundergroundspace,thesurroundingsoil,andthesurfacestructure.Theexcavationcancausedisturbancetothesoilandgroundwater,resultingingroundsubsidence.Moreover,thefoundationpitsmayaffectthestabilityandbearingcapacityoftheadjacentbuildings,bridges,androads.Therefore,itisnecessarytodesignandimplementareasonableexcavationplanandmonitoringsystemtoensurethestabilityandsafetyofthenewairportline.

GovernanceMeasuresandConstructionRecommendations

Inordertominimizetheinfluenceoftheabovefactorsonthegroundsubsidenceofthenewairportline,thefollowinggovernancemeasuresandconstructionrecommendationsareproposed:

1.Strengthenthemonitoringsystem:Installmonitoringpointsandinstrumentsintheconstructionareatocontinuouslymonitorthedisplacementandsettlementoftheground,aswellasthedeformationandvibrationoftheadjacentbuildings,roads,andpipelines.

2.Optimizetheexcavationplan:Analyzethesoilphysicalpropertiesandgroundwaterconditions,andadjusttheexcavationplanbasedonthesite-specificcharacteristicstoreducethedisturbancetothesoilandensurethesafetyandstabilityofthefoundationpits.

3.Improvetheconstructiontechnology:Adoptadvancedconstructiontechniques,suchassoilfreezing,grouting,anddrainage,tostabilizethegroundandcontrolthegroundwaterlevelduringtheexcavationprocess.

4.Establishemergencyresponsemeasures:Developasetofemergencyresponseplansandprocedurestodealwithunexpectedevents,suchaslandslide,collapse,andwaterinrushes.

Conclusion

GroundsubsidenceisacomplexandchallengingissueintheconstructionofthenewairportlineofBeijingRailTransit.Themultipleinfluencingfactors,suchasundergroundbuildings,soilphysicalproperties,andexcavationactivities,shouldbethoroughlyinvestigatedandanalyzedtoensurethesafetyandstabilityofthenewairportline.Therefore,itisnecessarytoadoptcomprehensivegovernancemeasuresandconstructionrecommendationstoachieveproperriskmanagementandensurethesuccessfulcompletionandoperationofthenewairportlineInordertoaddressthepotentialrisksassociatedwiththeconstructionofthenewairportlineinBeijing,itisessentialtoadoptacomprehensiveandstrategicapproachtoriskmanagement.Thiswillrequiretheidentificationandanalysisofallpotentialrisksandthedevelopmentofeffectivemitigationstrategiestoaddresstheserisks.

Oneimportantfactorthatmustbeconsideredwhenimplementingriskmanagementstrategiesisthepotentialimpactofundergroundbuildingsonthestabilityofthenewairportline.Theconstructionandoperationoftheairportlinemaycausesubsidenceandinstabilityofthesoilduetotheexcavationactivitiesandtheweightofthenewairportline.Thiscanleadtostructuraldamagetotheundergroundbuildingsandotherinfrastructuresnearby,aswellasposearisktothesafetyofthepassengersandworkersonthenewairportline.

Tomitigatetheimpactofundergroundbuildingsonthenewairportline,itisessentialtoconductacomprehensivesurveyofexistingundergroundstructuresintheareaandassesstheirpotentialimpactonthestabilityofthenewairportline.Additionally,itmaybenecessarytoadjustthedesign,alignment,anddepthofthenewairportlinetominimizetheimpactontheexistingundergroundstructures.

Anotherfactorthatmustbetakenintoaccountwhenimplementingriskmanagementstrategiesisthephysicalpropertiesofthesoilintheareasurroundingthenewairportline.Thesoiltype,moisturecontent,andotherphysicalpropertiescansignificantlyimpactthestabilityofthenewairportline,andtheexcavationactivitiesmaycausefurtherinstabilityofthesoil.

Tomitigatetheimpactofsoilinstabilityonthenewairportline,itisessentialtoconductathoroughsoilinvestigationandanalysisthatconsidersthevariabilityofthesoilconditionsatdifferentdepthsandlocationsaroundthenewairportline.Thiswillhelptoidentifypotentialareasofinstabilityanddevelopappropriatemitigationstrategiestoaddressthem.

Inadditiontoaddressingthepotentialimpactsofundergroundstructuresandsoilinstability,itisalsoimportanttoconsiderthepotentialrisksassociatedwiththeexcavationactivitiesthemselves.Theexcavationofsoilandrockcanposearisktothesafetyofworkersontheconstructionsite,aswellastonearbystructuresandinfrastructures.

Tomitigatetherisksassociatedwithexcavationactivities,itisessentialtoadoptappropriatesafetymeasures,suchastheuseofprotectiveequipment,implementingsafetyprotocols,andconductingregularinspectionsandmaintenanceofequipmentandinfrastructureontheconstructionsite.

Overall,thesuccessfulconstructionandoperationofthenewairportlineinBeijingwilldependonacomprehensiveandstrategicapproachtoriskmanagementthatconsidersallpotentialrisksanddevelopseffectivemitigationstrategies.Byaddressingthepotentialimpactofundergroundstructures,soilinstability,andexcavationactivities,itispossibletoensurethesafetyandstabilityofthenewairportline,aswellasthesafetyofworkersandpassengersinvolvedinitsconstructionandoperationInadditiontotherisksrelatedtotheconstructionandoperationofthenewairportlineinBeijingmentionedearlier,thereareotherfactorsthatneedtobeconsidered.Forinstance,theenvironmentalimpactoftheprojectneedstobeassessedandaddressedinordertopreventanynegativeconsequencesonthesurroundingecosystem.ThiscanbedonebyconductinganEnvironmentalImpactAssessment(EIA)thatanalyzesthepotentialeffectsoftheprojectontheair,water,soil,andbiodiversityofthearea.BasedontheresultsoftheEIA,appropriatemeasurescanbetakentomitigateanynegativeimpacts.

Anotherimportantriskfactoristhepotentialforaccidentsandemergenciesduringtheconstructionandoperationoftheairportline.Thiscouldincludeincidentssuchasfires,naturaldisasters,ortechnicalfailures.Toaddresstheserisks,itisimportanttodeveloparobustemergencyresponseplanthatidentifiespotentialhazards,outlinesproceduresfordealingwithemergencies,andtrainsrelevantpersonneltorespondappropriatelyincaseofincidents.

Moreover,thenewairportlinewillhaveanimpactonthetrafficandtransportationsystemofthesurroundingareas.Thiscouldleadtocongestion,increasedtrafficaccidents,andothertransportation-relatedrisks.Toaddresstheseissues,itisimportanttoconductathoroughtrafficimpactassessmentthatidentifiespotentialrisksanddevelopsappropriatemitigationmeasuressuchastrafficmanagementstrategies,roadexpansions,andpublictransportati