城市供水管网风险分析及评价

城市供水管网风险分析及评价AssessmentandAnalysisoftheRisksintheMunicipalWaterSupplyPipelineNetwork基金资助：国家自然科学基金重点项目：城市供水管网突发性事故应急处理/管理系统（50978213）FinancialSupport:TheNationNaturalSeieneeFoundationProject:SuddenAccidentEmergencyTreatment/ManagementSystemofUrbanWaterSupplyNetwork(GrantNo.50978213)西安建筑科技大学硕士论文城市供水管网风险分析及评价专业：市政工程硕士生：邢翔轩指导教师：黄廷林教授摘要随着城市建设的快速发展，城市供水管网的规模也在不断扩大，伴随而来的供水安全隐患也越来越多，城市供水管网风险分析及评价已经成为一项重要研究课题。本课题以A市的供水管网系统为研究对象，对其管网供水分界线上的水质指标进行检测分析；同时利用A市2010年爆管记录资料，对其进行不同方面的整理、归类与分析，以全面了解当前管网中存在的爆管原因及规律，从而对A市供水管网的水质和爆管现象给出合理的评价及应对措施。本研究的结果如下：一水风险评价及控制措施（1）65%的测点出现在过余氯不达标现象，其中3个测点余氯达标率低于50%。太华路凤城三路口的余氯检测最大值为0.04mg/L。供水分界线是不同水质的交汇处，水质的不同会出现营养互补和生物化学反应等现象，造成余氯的损耗；此外水力停留时间长也是分界线上管网水余氯偏低的重要原因。（2）65%的测点出现在过浊度不达标现象，达标率在80%以下的点有5个，其中长乐东路纺北路口测点的浊度达标率为63.3%。此外有两处测点浊度检测最大值均高出标准3倍以上。供水分界线上管道处于不同水质水流状态下，管壁更易于被腐蚀，水流方向和流速发生变化时，附着在管壁上的沉积物和生物膜被冲起，是造成浊度升高的主要原因。（3）35%的测点出现过铁超标，朱宏路测点检测铁含量最高值为0.5169mg/L，除汉城北路测点锰含量出现过超标，其余测点锰含量均低于国家标准。定期对管道冲洗，更换老化管道，以及改进水厂处理工艺能够有效地改善饮用水水质。二爆管风险评价及控制措施西安建筑科技大学硕士论文管材老化以及地基沉降是管道爆管的主要原因，占爆管总数的80%。南郊地区的爆管大部分和地裂缝活动有关，地裂缝活动引起的爆管占75.9%。管道爆管的表现形式主要是管道接口处漏水或断裂。尽量避免使用灰口铸铁管、镀锌钢管。小管径可以采用PE管、钢塑复合管，DN100以上管径可以采用球墨铸铁管、钢管。在易发生地基沉降的地段应采取管道基础加固措施，如加设伸缩器。在敷设易受外界影响而腐蚀的管段时，应采取特殊的防腐措施。在地裂缝活动非常活跃的地方管道应敷设在套管内，节点尽量采用柔性连接。关键词：城市管网；供水分界线；水质风险；爆管西安建筑科技大学硕士论文AssessmentandAnalysisoftheRisksintheMunicipalWaterSupplyPipelineNetworkSpeciality:EnvironmentalscienceAuthor:XingXiangxuanSupervisor:Prof.HuangTinglinABSTRACTWiththerapiddevelopmentofurbanconstruction,thescaleofurbanwatersupplynetworksisalsoexpandingbutaccompaniedbymoreandmorerisksinwatersupplysecurity.Riskanalysisandassessmentofurbanwatersupplynetworkshavebeenanimportantresearchsubject.ThewatersupplynetworkinCityAistakenasaresearchobjectandthewaterqualityindicatorsonthedividinglinearedetectedandanalyzedinthisthesis.Inordertounderstandcomprehensivelythecausesandintrinsicproblemsofthepipeexplosioninthecurrentsupplynetwork,therecordsofthepipeexplosioninCityAoftheyear2010isusedatthesametimetoconductsomecollation,classificationandanalysisofdifferentaspects.Attheend,areasonableassessmentismadeandpreventivemeasuresaretakenaboutthewaterqualityandthephenomenonofpipeexplosion.Themainresultsofthisstudyareasfollows:1Riskassessmentofthewaterqualityanditscontrolmeasures（1）At65%ofthemeasurementpoints,theresidualchloridecannotcomeuptothequota.Iisobervedthatatthreeofthemeasurementpoints,theresidualchlorideislowerthanthequota.ThemaximumvalueofresidualchlorideattheCrossroads3ontheTaihuaavenueis0.04mg/L.Thedividinglineofwatesupplyisajunctionofdifferentwaterqulities.Therefore,therewilloccurmutualcomplementofnutritioussubstancesandbio-chemicalreactionsduetothedifferenceofwaterquality,causingthelossofresidualchloride.Besides,thelongstayofthehydraulicpowerisalsoan西安建筑科技大学硕士论文importantcauseofresidualchloridetobeonthelowsideinthepipelinenetworkonthedividingline.（2）At65%ofthemeasurementpoints,therehasoccuredsuchaphenomenonastheturbiditydidnotexceedthequota.Thereareonlyfivemeasuremntpointswhosequota-hitratioproportionwaslowerthan80%.Amongthefive,thequota-hitratioproportionofturbidityatthemeasurementpointneartheFangbeicrossroadsontheChangleavenueeastwas63.3%.Inaddition,themaximumvalueofturbidityattwopointsweredetectedasthreetimeshigherthanthestandard.Therefore,therewilloccurmutualcomplementofnutritioussubstancesandbio-chemicalreactionsduetothedifferenceofwaterquality.Onthedividinglineofwatersupply,pipesstayinthestateofdifferentwaterqualitiesandatdifferentspeedsofflowofwater,sotheirwallsareeasytocorrode.Whenthedirectionandspeedoftheflowofwaterchange,thesedimentsandbio-membranesonthepipewallsarewashedoff,whichistheprincipalcauseofariseofturbidity.（3）At35%ofthemeasurementpointstherehasoccurredsuchaphenomenonasironexceededthequota.AtthemeasurementpointontheZhuhongavenue,thehighestvalueoftheironcontentwasdetectedas0.5169mg/L.ExceptthemeasurementpointontheHanchengnorthroadwheremanganesehasonceexceededthequota,themanganesecontentattherestofthemeasurementpointsarelowerthanthenationalstandard.Thepipesneedtobewashed,agingpipesreplacedandtheprocessingtechnologyatthewaterstationsimprovedatregulartimes.Inthisway,thequalityofdrinkingwatercanbeimprovedeffecively.Thepipesneedtobewashed,agingpipesreplacedandtheprocessingtechnologyatthewaterstationsimprovedatregulartimes.Inthisway,thequalityofdrinkingwatercanbeimprovedeffecively2RiskofthepipeexplosionandcorrespondingcontrolmeasuresFoundationsettlementandtubularageingareleadingcauseofpipeexplosion,accountingfor80%ofthetotal.Thepipeexplosioninsouthernsuburbscloselyrelatestogroundfissure,andpercentageofpipeexplosioncausedbygroundfissuremovementsis75.9%.themainformofpipeexplosionisleakageofpipeinterfaceorbreakage.西安建筑科技大学硕士论文Trytoavoidtheuseofgray-castironpipeandgalvanizedsteelpipe.PEpipeandplasticcompositepipewouldbebestusedforsmalldiameter.ductileironpipeandsteelpipewouldbebestusedforthosepipeswhosediameterwasgreaterthan100mm.Atthesectionwhereitiseasyforthebasementtosettle,reinforceingmeasures,suchasanadditionofexpansionpipes,oughttobetaken.Whenthepipesthatareeasytobeaffecte