地铁建设与环境保护

地铁建设与环境保护MetroConstruction&EnvironmentalProtection前言INTRODUCTION地铁建设大多是在建成区进行，对工程周边的环境保护至关重要。Mostjobsitesareinurbanarea,Environmentalprotectionisofutmostimportance.一方面,国内外地铁建设过程中产生的大小事故，时有所闻。Ononeside,bigorsmallincidentsoccurredtimely,bothhomeandabroad.另一方面,大多数地铁建设工程则未对周边环境造成明显的影响。Ontheotherside,themajoritydonothaveanyimpacttotheenvironment.根据本人从事地铁建设之经验,参照国内外的实例,提出如下意见：Accordingtomypersonalexperienceinmetroconstruction,takingcasesbothhomeandabroadasreference,thefollowingismypointofview：地铁建设对环境的影响是可控的、事在人为、只要认真对待、可以做到对环境的影响降低到可接受的程度，甚至到不被觉察的地步Theimpacttotheenvironmentiscontrollable,wecanreducetheimpacttoanacceptablelevel,providedwetreatitseriously,eventoanunnoticeablestate近年来的重大事故SIGNIFICANTINCIDENTSINRECENTYEARS2003年上海地铁四号线区间坍塌事故2003,ShanghaiMetroLine4Incident2004年新加坡地铁环线区间坍塌事故2004,SingaporeCircleLineIncident2006年南京地铁二号线区间坍塌事故2006,NanjingMetroLine2Incident2008年杭州地铁一号线车站坍塌事故2008,HangzhouMetroLine1Incident高雄捷运区间坍塌事故KaohsiungRapidTransitIncidentIncidentofShanghaiMetroLine4July12003IncidentofSingaporeCircleLine20thApril2004IncidentofNanjingMetroLine2IncidentofHangzhouMetroLine112thNov2008IncidentofKaoXiongMetro国内外成功的实例FACTSOFLITTLEIMPACTBOTHHOMEANDABROAD上世纪六十年代上海地铁起步，两台六米直经盾构穿越一座三层混合结构建筑、一条下有各种管线的马路、二幢作为外国领事馆用房的花园洋房。当时因保密关系外人根本不知有地铁在他们脚下施工。到如今，这两幢花园洋房依然完好无损Inlate1960’,twosemi-blindshieldsweredrivenunderneathtwobuildingsoccupiedbytheCzechandtheNorwayConsulateGeneral.ThiswasthefirstshieldtunnelinginChina。ThetwintunnelsweredrivenquietlywithnodisturbancetothesebuildingsTheCzechConsulateGeneralTheNorwayConsulateGeneral上世纪六十年代,伦敦希斯罗机场在繁忙的跑道下,用气压盾构建造了一条内径十米的货运隧道,隧道复土仅七米,跑道的容许沉降值为十一毫米.施工结果,地层损失率仅为0.25%In1960’s,an10mi.d.cargotunnelwasdrivenunderneaththebusyrunwayoftheHeathrowAirPort,London.Thegroundcoverwas7m,theallowablesettlementwasspecifiedas11mm.Acompressedairshieldmachinewasusedtodrivethetunnel.Thegroundlosswas0.25%.SirAlanMuir-woodwasthedesigner东京新宿二条直径十一米的高速道路隧道在既有地下建筑物下和在上有地铁、下有电信及十三号线隧道中穿越，对周围构筑物的干扰甚微InSinjukuTokyo，twinboredroadtunnels,11mindiameter,weredrivenunderneathanundergroundstructureandpassedthroughaspacebetweenacutandcovermetrotunnelandanutilitytunnelwithverylittleimpacttothesurroundings去年上海地铁九号线成功地在距既有的地铁一号线上方83厘米，和在距1.6米直径的下水道仅43厘米的下方穿越Lastyear,twinboredtunnelsofmetroline9ofShanghaiMetropassedabovetheexistingMetroLine1withaclearanceonly83cmandunderneatha1.6mseweragetunnelwithaclearanceof43cm1.66m0.83m4.25m2.盾构浅覆土穿越地铁1号线隧道及Ф1600雨水管－4.635+4.63上行线下行线+4.98－4.135上行线下行线83cm43cmФ1600雨水管天平路雨水管剖面图如何减少对环境的影响HOWTOMINIMIZETHEIMPACT用明挖法施工的车站CUTANDCOVERSTATIONBOX盖挖逆筑较顺筑可减少对环境的影响Topdownconstructionmaydecreasetheimpactascomparedwithbottomupconstructionmethod增加围护结构的刚度，即增加其截面摸量Increasetherigidityoftheshoringstructure增加、增强支撑体系Increaseandstrengthenthestrutting增加被动抗力，即在被动区进行地基改良，更有在被动区预先做刚性支撑Increasethepassivestrength,thatisgroundimprovement,evenconstructarigidstrutpriortoexcavation注意各个环节，往往细节决定成败Takecareofeverydetails,sometimesdetailsdetermine及时支撑，施加预应力、复加预应力Applythestrutsontime,pre-stressandre-stressit重视监测，根据监测资讯、及时采取适当措施Emphasizethemonitoringsystem,promptmeasuresshouldbetakenConnectionStiffenerPlate小用盾构法施工的区间隧道RUNNINGTUNNELBYSHIELDMETHOD仔细研究工程地质和水文地质，选用相适应的盾构机Carefullystudythegeologyandhydrology,selectappropriateshieldmachine选择何处、那种技术对盾构进行干预。如换刀、换盾尾密封等Selecttherightplaceofinterventionandrightmethodtochangethecutterbits,tailseals选择注浆系统及注浆材料及有关参数Selecttheproperinjectionsystemandgrout选择合理的监测系统，籍以及时修正盾构推进各有关参数，严格掌握最低地层损失率。国外最新进展是采用实时监测系统及时修正各参数，力求做到对环境零影响Selectpropermonitoringsystem,inordertodirecttheshielddrive.Strictlycontrolthevalueofgroundloss.Recentlytherearetechniquesabroad,whicharestrikingtowardzeroimpacttotheenvironmentbyrealtimemonitoringandadjustment补偿注浆COMPENSATIONGROUTING补偿注浆.这是一种有别于二次注浆的新理念.用之于环境保护有特殊需要之处.国内的二次注浆,有时称为跟踪注浆,它在用注浆作为保护环境的辅助措施上是一回事,但在注浆地点和方法上有所区别.Compensationgrouting.Thisisanewideadifferentwithsecondarygrouting,whichiswidelyusedinChina.Theyarebothusedasanauxiliarymeasureforenvironmentprotection,butdiffersintheplaceandthemethodologyofgrouting.实时监测REALTIMEMONITORING地铁建设过程中对周边环境的影响有一个从小到大的发展过程,加以监测是必要的。第三方监测就是我们的眼睛，但在关键时间、关键地段，往往监测间隔太长，不能及时指导施工。近年来出现的实时监测弥补了此缺陷Theenvironmentimpactduringmetroconstructionexperiencedfromsmalltobigprocess.Thirdpartymonitoringactsasoureye,butduringcriticaltimeandlocation,themonitoringfrequencyisalittletoolong,cannotguidetheconstruction.Realtimemonitoring,whichappearedrecentyearscoveredthiskindofdefect.实时监测技术目前在上海常用于对既有隧的沉降监测。它是由铺设于隧道内的电子水准仪来实施的。RealtimemonitoringisusedinShanghaitomonitorthesettlementofexistingtunnel。Itisrealizedbyelectroniclevelsfixedintunnel.在国外,实时监测技术还应用于沉降监测。它是由全站仪,菱镜,数码相机,电脑组成.RealtimemonitoringisalsousedtomonitorgroundsettlementinWesterncountries.Thissystemiscomprisedofallstationtheodolite,prism,digitalcamera,computer。VanderPoeletal.(2005)恐Remotereal-timemonitoringusingimageanalysis(Takeetal,2005)减振VibrationAttenuation轨道减振措施之优劣影响环境的程度。在常用的措施外,介绍一种措施,见诸捷克地铁。Themeasuretoattenuatetherailvibrationmatterstheenvironmentstrongly.Asidethemeasuresfamiliartous,anewone,ascanbeseeninCzechmetro。Remotereal-timemonitoringusin