北京轨道交通新机场线地面沉降特征及影响因素分析

北京轨道交通新机场线地面沉降特征及影响因素分析摘要：

近年来，北京市轨道交通发展迅速，新建的北京大兴国际机场线也是其中之一。然而，随着地面的机动车辆、建筑物和地下管道等工程的不断增多，轨道交通施工和运营引起了地面沉降的问题。本文以北京轨道交通新机场线为研究对象，对其地面沉降的特征及影响因素进行分析。

首先，对新机场线地面沉降时间、空间分布特征进行了分析，得出了机场线周边地面沉降较为严重的结论。然后，探究了不同施工阶段对地面沉降的影响及作用机理。结果表明，新机场线近期施工对周边地面沉降影响最大。接着，根据多方因素影响，结合实际监测数据，探究了地下建筑物、土壤物理性质和基坑土方开挖等因素对新机场线地面沉降的影响因素。最后，针对影响因素，提出了相应的治理措施和建设建议，为新机场线的安全稳定运营提供保障。

关键词：北京轨道交通、新机场线、地面沉降、影响因素、施工阶段、建设建议

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