液壓防洪或通航建筑物的結(jié)構(gòu)變形的調(diào)查技術(shù)指導(dǎo)畢業(yè)論文外文文獻(xiàn)翻譯

英文原文及譯文Thisresearchprovidestechnicalguidanceforperformingprecisestructuraldeformationsurveysoflocks，dams，andotherhydraulicfloodcontrolornavigationstructures．Accuracy，procedural，andqualitycontrolstandardsaredefinedformonitoringdisplacementsinhydraulicstructures．Generalplanningcriteria，fieldandofficeexecutionprocedures，datareductionandadjustmentmethods，andrequiredaccuracyspecificationsforperformingstructuraldeformationsurveysareprovided．Thesetechniquesareapplicabletoperiodicmonitoringsurveysonearthandrock-filldams，embankments，andconcretestructures．Thisresearchcoversbothconventionalandsatellite(GPS)deformationsurveymethodsusedformeasuringexternalmovements．Dams，locks，levees，embankments，andotherfloodcontrolstructuresaresubjecttoexternalloadsthatcausedeformationandpermeationofthestructureitself,aswellasitsfoundations．Anyindicationofabnormalbehaviormaythreatenthesafetyofthestructure．Carefulmonitoringoftheloadsonastructureanditsresponsetothemcanaidindeterminingabnormalbehaviorofthatstructure．Ingeneral，monitoringconsistsofbothmeasurementsandvisualinspections．Tofacilitatethemonitoringofhydraulicstructures，theyshouldbepermanentlyequippedwithproperinstrumentationandmonitoringpointsaccordingtothegoalsoftheobservation，structuretypeandsize，andsiteconditions．1-1．ImportanceofStructuralMonitoringThesecurityofstructurerequiresperiodicmonitoringmaintenanceandrestoration.Excessiveandnon-stabilizeddeformationsareoftenobservedandalthoughtheyrarelyaffecttheglobalstructuralsecurity，theycanleadtoserviceabilitydeficiencies.Furthermore，accurateknowledgeofthebehaviorofstructuresisbecomingmoreimportant．Monitoringbothinthelongandshorttermhelpstoincreasetheknowledgeoftherealbehaviorofthestructuresandintheplanningofmaintenanceintervention．Inthelongterm，thestaticmonitoringneedsofanaccurateandverystablesystemabletorelatedeformationmeasurementsoftenspacedoverlongperiodsoftime.Ontheotherside,dynamicanalysisofstructures，orshorttermmonitoring,requiresofasystemcapableofmeasuringdeformationsoccurringoverrelativelyshortperiodsoftime．Currentlyavailablemonitoringtransducers，suchasinductiveandGPS,microbendingsensorsoraccelerometersareonlysuitableforperformingmeasurementsinashortrangeoffrequencies-Moreoversomeofthesetechniquesarestillinthedevelopmentstageandonlyusedinlaboratoryexperiments(31．Othersystemsdonotofferenoughinformationaboutthedesiredparameter(forexample，accelerometersgiveUSthefrequencyofvibration，butdisplacementscalculationsarenotaccurate)．Thus，thereisarealneedofauniquesensorcapableofcovetingstructuraldeformationrequirementsinwiderangeoffrequencies.WhyPermanentMonitoringisNecessary?Bridgespatialdisplacementisafactorrelativelyfaciletomeasureforshorttermconditionbutdifficultforlongtermmonitoring．Infact，itisgenerallynotpossibletoputmechanicalgaugesinpermanenceunderabridgeorplaceageometermeasuringeveryhourbyopticallevelingprocess.Permanentmonitoringisnecessarytocomparethespatialdisplacementduetonon-temperatureeffect．Infact，effectsonbridgearedueto5causes：1．Permanentload(theweight)2．Staticandvariableload(trafficload，windload?)3．Thermaleffect4．Evolutionofthematerialproprieties(shrinkage，creep?)5．Disasterinthebridge(crack,supportsettlement.a．Structuraldeformation．Dams，locks，levees，embankments，andotherfloodcontrolstructuresaresubjecttoexternalloadsthatcausedeformationandpermeationofthestructureitself，aswellasitsfoundations．Anyindicationofabnormalbehaviormaythreatenthesafetyofthestructure.Carefulmonitoringoftheloadsonastructureanditsresponsetothemcanaidindeterminingabnormalbehaviorofthatstructure．Ingeneral，monitoringconsistsofbothmeasurementsandvisualinspections．Tofacilitatethemonitoringofhydraulicstructures，theyshouldbepermanentlyequippedwithproperinstrumentationandmonitoringpointsaccordingtothegoalsoftheobservation，structuretypeandsize，andsiteconditions．b．Concretestructure．Itshouldbeintuitivethatdeformationsandperiodicobservationswillvaryaccordingtothetypeofstructure．Differencesinconstructionmaterialsareoneofthelargerinfluencesonhowastructuredeforms．Forexample，concretedamsdeformdifferentlythanearthenorembankmentdams．Forconcretedamsandotherconcretefloodcontroldevices,deformationismainlyelasticandhighlydependentonreservoirwaterpressureandtemperaturevariations．Permanentdeformationofthestructurecansometimesoccurasthesubsoiladaptstonewloads，concreteaging，orfoundationrockfatigue．Suchdeformationisnotconsideredunsafeifitdoesnotgobeyondapredeterminedcriticalvalue．Therefore，periodicobservationsaretypicallyconfiguredtoobservingrelativelylong-termmovementtrends，toincludeabnormalsettlements，heaving,orlateralmovements．Conventionalgeodeticsurveymethodsfromexternalpointsandofcentimeter-levelaccuracyaresufficienttomonitortheselong-termtrends.Highlyaccurate，short-termdeflectionsorrelativemovementsbetweenmonolithsduetovaryingtemperatureorhydraulicloadingaremorerarelyrequired.Thesemayincludecrackmeasurementsorrelativemovementsbetweenmonolithsoverdifferenthydraulicloadings.Relativemovementdeflectionstothe+0.01-inchaccuracylevelarecommon.c．Earthenembankmentstructures．Earthenorembankmentdamsandleveesobviouslywilldeformaltogetherdifferentlythanconcreteones．Withearthendams，thedeformationislargelycharacterizedasmorepermanent．Theself-weightoftheembankmentandthehydrostaticpressureofthereservoirwaterlargelyforcethefillmateria1(andinturn，thefoundation,ifittoconsistsofsoil)tosettle，resultinginaVerticaldeflectionofthestructure.Thereservoirwaterpressurealsocausespermanenthorizontaldeformationperpendiculartotheembankmentcenterline．Withearthendams，elasticbehaviorisslight．Deformationsurveyaccuracyrequirementsarelessrigidforearthenembankments，andtraditionalconstructionsurveymethodswillusuallyprovidesufficientaccuracy．Typicalsurveysincludeperiodicmeasurementofembankmentcrestelevationsandslopestomonitorsettlementsandslopestability．Forembankmentstructures，surveysaccuraciesatthe+0.1footlevelareusuallysufficientformonitoringlong-termsettlementsandmovements．d．Long-termdeformationmonitoring．Dependingonthetypeandconditionofstructure，monitoringsystemsmayneedtobecapableofmeasuringbothlong-termmovementtrendsandshort—termloadingdeformations．Long-termmeasurementsarefarmorecommonandsomewhatmorecomplexgiventheirexternalnature．Long-termmonitoringofastructure’movementstypicallyrequiresobservationstomonitoringpointsonthestructurefromexternalreferencepoints．Theseexternalreferencepointsareestablishedonstablegroundwellremovedfromthestructureoritsconstructioninfluence．Theseexternalreferencepointsareinter-connectedandtermedthe”referencenetwork.”Thereferencenetworkmustalsobemonitoredatless．Frequentintervalstoensurethesereferencepointshavenotthemselvesmoved．Traditionalgeodeticsurveyinstrumentsandtechniquesmaybeemployedtoestablishandmonitorthereferencenetworkpoints．1-2．DeformationTechniquesa．Referenceandtargetpoints．Thegeneralprocedurestomonitorthedeformationofastructureanditsfoundationinvolvemeasuringthespatialdisplacementofselectedobjectpoints(targetpoints)fromexternalreferencepointsthatarefixedinposition．Bothterrestrialandsatellitemethodsareusedtomeasurethesegeospatialdisplacements．Whenthereferencepointsarelocatedinthestructure，onlyrelativedeformationisdetermine．Absolutedeformationordisplacementispossibleifthereferencepointsarelocatedoutsidetheactualstructure，inthefoundationorsurroundingterrainandbeyondtheareathatmaybeaffectedbythedamorreservoir．Subsequentperiodicobservationsarethenmaderelativetotheseabsolutereferencepoints．Assessmentofpermanentdeformationsrequiresabsolutedata．b.Referencepointnetwork.Ingeneral，forconcretedamsitisidealtoplacethereferencepointsinarockfoundationatadepthunaffectedbythereservoir．Oncepermanentlymonumented．Thesereferencepointscanbeeasilyaccessedtoperformdeformationsurveyswithsimplemeasurementdevices．Fixedreferencepointslocatedwithinthevicinityofthedambutoutsidetherangeofitsimpactareessentialtodeterminationofthedeformationbehaviorofthestructure．Thus,monitoringnetworksinthedamplaneshouldbesupplementedbyandconnectedtotriangulationnetworksandverticalcontrolwheneverpossible．c.Monitoringtechniques．Themonitoringmannersuchthatthedisplacementisofdamorfoundationdeformationmustbedoneinameasuredbothhorizontallyandvertically．Suchmeasurementsmustincludethefoundationandextendasfaraspossibleintoit．Redundancyisessentialinthisformofdeformationmonitoringandisachievedthroughmeasuringatthepointsintersectingtheorthogonallinesofthedeformationnetwork．Ifadamincludesinspectiongalleriesandshafts，deformationvaluesalongverticallinescanbeobtainedbyusinghangingandinvertedplumblinesandalonghorizontallinesbytraverses-bothofthesemethodsarestandardpracticefordeformationmonitoring．Wheretherearenogalleriesorshafts(e.g.,embankmentdams，thinarchdams，orsmallgravitydams),thesameresultcanbeachievedbyanorthogonalnetworkofsurveytargetsonthedownstreamface．Thesetargetsaresightedbyanglemeasurementsfromreferencepointsoutsidethedam．d．Relativedisplacementobservations．Amoreroutine，lesscostly，andmorefrequentmonitoringprocesscanbeemployedtomonitortheshorttermbehaviorofdamsbysimplyconfiningobservationtotrendsatselectedpointsalongthecrestandsometimesverticallines．Suchprocedurestypicallyinvolvesimpleanglemeasurementoralignment(supplementingthemeasuringinstallation)alongthecresttodeterminehorizontaldisplacement，andelevationdeterminationbylevelingtodetermineverticaldisplacement．Evenwiththismonitoringprocess，itisessentialtoextendlevelingtosomedistancebeyondtheabutments．Alternativemethodstothatdescribedincludesettlementgauges，hoselevelingdevices，orextensometer．Structuralstabilityassessmentsurveysmayberequiredthroughtheentirelifecycleofaproject，spanningdecadesinmanycases.Duringtheearlyplanningphasesofaproject,acomprehensivemonitoringplansshouldbedevelopedwhichconsiderssurveyrequirementsoveraproject’lifescycle，withagoalofeliminatingduplicateorredundantsurveystothemaximumextentpossible．Duringinitialdesignandpreconstructionphasesofaproject，referencepointsshouldbepermanentlymonumentedandsituatedinareasthatareconducivetotheperformanceofperiodicmonitoringsurveys．Duringconstruction，fixedmonitoringpointsshouldbeestablishedonthestructureatpointscalledforinthecomprehensivemonitoringplan．這項(xiàng)研究提供了精確的執(zhí)行鎖，水壩等液壓防洪或通航建筑物的結(jié)構(gòu)變形的調(diào)查技術(shù)指導(dǎo)。精度，程序和質(zhì)量控制標(biāo)準(zhǔn)，定義了水工建筑物位移監(jiān)測。一般規(guī)劃準(zhǔn)則，現(xiàn)場和辦公室執(zhí)行程序，數(shù)據(jù)壓縮和調(diào)整方法，并履行構(gòu)造變形調(diào)查提供所需的精度指標(biāo)。這些技術(shù)適用于在土石填大壩，堤防和混凝土結(jié)構(gòu)的定期監(jiān)測調(diào)查。該研究包括傳統(tǒng)的和衛(wèi)星（GPS）的變形測量用于測量外部動作使用的方法。大壩，船閘，堤壩，堤防等防洪結(jié)構(gòu)受外部負(fù)載引起的變形和結(jié)構(gòu)本身的滲透，以及它的基礎(chǔ)。跡象顯示任何異常行為可能危及結(jié)構(gòu)安全。仔細(xì)的結(jié)構(gòu)及其反應(yīng)給他們的負(fù)荷監(jiān)測可以幫助確定該結(jié)構(gòu)的異常行為。一般來說，監(jiān)測包括兩個(gè)測量和視覺檢查。為方便水工建筑物的監(jiān)測，他們應(yīng)該永久配備適當(dāng)?shù)膬x器和監(jiān)測點(diǎn)，根據(jù)觀察，結(jié)構(gòu)類型和大小，以及場地條件的目標(biāo)。1-1.結(jié)構(gòu)監(jiān)測的重要性對結(jié)構(gòu)的安全性要求定期監(jiān)測維護(hù)和恢復(fù)。過度和非穩(wěn)定變形是經(jīng)常觀察，雖然他們很少會影響整體結(jié)構(gòu)安全，他們可能會導(dǎo)致服務(wù)能力的不足。此外，對結(jié)構(gòu)行為的準(zhǔn)確知識變得越來越重要。無論是從長期和短期的監(jiān)測有助于提高在維護(hù)規(guī)劃的干預(yù)的結(jié)構(gòu)知識和實(shí)際行為。從長遠(yuǎn)來看，靜態(tài)的監(jiān)測需要一個(gè)準(zhǔn)確的和非常穩(wěn)定的系統(tǒng)能夠與常常在很長一段時(shí)間間隔的變形測量。在另一邊，動態(tài)分析的結(jié)構(gòu)，或短期監(jiān)測，需要一個(gè)系統(tǒng)的測量變形，跨越時(shí)間相對短的時(shí)期發(fā)生的能力。目前可提供的監(jiān)測傳感器，如感應(yīng)和GPS，微彎傳感器或加速度只對執(zhí)行中的頻率，而且這些技術(shù)的一些短距離的測量適合仍處于發(fā)展階段，只有在實(shí)驗(yàn)室實(shí)驗(yàn)中使用。系統(tǒng)不提供有關(guān)所需的參數(shù)足夠的信息（例如，加速使美國的振動頻率，但位移計(jì)算不準(zhǔn)確）。因此，有一個(gè)獨(dú)特的傳感器實(shí)際需要覬覦在寬的頻率范圍內(nèi)構(gòu)造變形能力的要求。什么長期監(jiān)測是必要的？。橋空間位移是一個(gè)因素來衡量比較淺顯短期條件，但長期監(jiān)測困難。事實(shí)上，一般不可能把持久性機(jī)械儀表橋下或地方每一個(gè)幾何學(xué)家光學(xué)測量矯直過程小時(shí)。長期監(jiān)測是必要的空間位移比較由于非溫度效應(yīng)。事實(shí)上，對橋梁的影響是由于5個(gè)原因：1、永久荷載（自重）2、可變負(fù)載（交通荷載，風(fēng)荷載 ?）3、溫度效應(yīng)4、材料禮演進(jìn)（收縮，徐變 ?）5、災(zāi)害中橋（裂紋，支持解決）a、結(jié)構(gòu)變形。大壩，船閘，堤壩，堤防等防洪結(jié)構(gòu)受外力造成變形和結(jié)構(gòu)本身的滲透，以及它的基礎(chǔ)。跡象顯示任何異常行為可能危及結(jié)構(gòu)安全。仔細(xì)的結(jié)構(gòu)及其反應(yīng)給他們的負(fù)荷監(jiān)測可以幫助確定該結(jié)構(gòu)的異常行為。一般來說，監(jiān)測包括兩個(gè)測量和視覺檢查。為方便水工建筑物的監(jiān)測，他們應(yīng)該永久配備適當(dāng)?shù)膬x器和監(jiān)測點(diǎn)，根據(jù)目標(biāo)的觀察，結(jié)構(gòu)類型和大小，以及場地條件 .b、混凝土結(jié)構(gòu)。它應(yīng)該是直觀的變形和定期觀測將根據(jù)不同的結(jié)構(gòu)類型。在建筑材料上的差異是如何結(jié)構(gòu)變形較大的因素之一。例如，混凝土大壩變形不同于土或土石壩。對于混凝土大壩等混凝土防洪設(shè)備，主要是彈性變形和高度水庫水壓力和溫度變化而定。永久變形的結(jié)構(gòu)有時(shí)能發(fā)生的底土適應(yīng)新的荷載作用下 ,混凝土老化或地基巖石疲勞。這樣的變形是不被認(rèn)為是不安全的 ,如果它不超出預(yù)定的臨界值。通常,定期觀測e配置為觀察較長期的運(yùn)動趨勢 ,包括異常聚落、脹,或側(cè)方運(yùn)動。傳統(tǒng)的大地測量方法的精度部分 ,就足以監(jiān)控這些長期趨勢。高度準(zhǔn)確,短期撓度或相對運(yùn)動變化之間由于溫度和單體液壓加載更為罕見要求。這些可能包括裂紋尺寸之間的相對運(yùn)動或在不同單體液壓載荷。相對運(yùn)動到 +0.01英尺撓度的準(zhǔn)確性水平是很普遍的。c、路基結(jié)構(gòu)。大壩和防洪堤瓦或路基變形完全不同的顯然會的具體的工作。擁有沉默的大壩,變形是很大隨著越來越多的永久特征。自重的的路基和儲層的流體靜力壓水充填材料很大程度上力 (并反過來,基礎(chǔ)上,如果它包括土壤)平靜下來,導(dǎo)致在一個(gè)垂線偏差的結(jié)構(gòu)。水庫水的壓力也會引起永久性的橫向變形,垂直于路堤中心線。擁有沉默的大壩,與時(shí)間相關(guān)的彈性行為是輕微的。調(diào)查精度要求的變形是不那么僵硬為陶制的堤防、與傳統(tǒng)施工測量方法通常會提供足夠的精度。典型調(diào)查包括定期測量路基頂海拔、坡遺址和邊坡穩(wěn)定性監(jiān)測。路基結(jié)構(gòu),調(diào)查精度為+0.1英尺的足夠水平監(jiān)測通常是長期安置點(diǎn)和動作。d、變形監(jiān)測。根據(jù)類型和狀態(tài)監(jiān)測系統(tǒng)結(jié)構(gòu) ,可能需要能夠測量和長期運(yùn)動趨勢和短期加載變形。長期的測量是較為常見的事物 ,遠(yuǎn)遠(yuǎn)更復(fù)雜的、在一定程度上給他們的外部自然。構(gòu)造了一種長期監(jiān)測的移動通常需要觀察來監(jiān)測布點(diǎn)在結(jié)構(gòu)上由外部參考點(diǎn)。這些外部參考點(diǎn)都是建立在穩(wěn)定地好除去的結(jié)構(gòu)或其建筑的影響。這些外部參考點(diǎn)都是互相連接 ,這種被稱為“參考網(wǎng)絡(luò)?！眳⒖季W(wǎng)絡(luò)也必須監(jiān)控在更少。頻繁的時(shí)間間隔 ,以確保這些參考點(diǎn)沒有自己感動。傳統(tǒng)的大地測量儀器和技術(shù)可能被雇用來建立和監(jiān)控網(wǎng)絡(luò)的參考點(diǎn)。1-2.變形技術(shù)a、參考點(diǎn)和目標(biāo)點(diǎn)。一般程序監(jiān)控的變形結(jié)構(gòu)及其基金會的空間位移的涉及到測量目標(biāo)選擇的物體的點(diǎn) (分)從外在的參考點(diǎn),被固定在位置。陸地和衛(wèi)星方法用于測量這些地理位移。當(dāng)參考點(diǎn)是位于結(jié)構(gòu) ,只有相對的變形是確定的。絕對變形或位移是可能的,如果參考點(diǎn)是位于外的實(shí)際結(jié)構(gòu) ,在基礎(chǔ)和周圍的地形和超越的區(qū)域,可能會受大壩和油氣藏。隨后的周期性的觀察人最后相對于這些絕對參考點(diǎn)。永久變形的評估需要絕對的數(shù)據(jù)。b、參考點(diǎn)的網(wǎng)絡(luò)。一般來說,對混凝土壩是理想的地方參考點(diǎn)在巖石地基在深度不受水庫。一旦永久。這些參考點(diǎn)可以很容易地訪問調(diào)查簡單履行變形測量裝置。位于固定的參考點(diǎn),該隊(duì)在賽場附近的大壩 ,但外界對其影響范圍的確定是必要的,結(jié)構(gòu)的變形行為。因此,在大壩監(jiān)測網(wǎng)絡(luò)飛機(jī)應(yīng)該為輔的三角并連接到網(wǎng)絡(luò)和垂直控制只要有可能。c、測技術(shù)。這樣的方式,監(jiān)測大壩位移或地基變形的測量必須做在橫向和縱向排列。而這些測量必須包括基礎(chǔ)和延長盡可能帶進(jìn)那城。 冗余是根本的在這種形式的變形監(jiān)測,取得了較好的效果,通過測量正交線相交的點(diǎn)的變形網(wǎng)絡(luò)。 如果一個(gè)大壩包括檢驗(yàn)畫廊和軸、變形值沿垂直的線使用 ,可制得掛和反垂直線條和沿水平臺詞h對這些方法的標(biāo)準(zhǔn)實(shí)踐為變形監(jiān)測。里面沒有畫廊或軸 (例如,土石壩、薄拱壩壩,或小型重力),同樣的結(jié)果,才能實(shí)現(xiàn)由正交的網(wǎng)絡(luò)調(diào)查的目標(biāo)在距離下游的臉。這些目標(biāo)是通過角度測量 ,在有視力的參考點(diǎn)外面的大壩。d、位移觀測結(jié)果。一種較常規(guī)、低成本和更頻繁的監(jiān)控過程可以用來監(jiān)控短期行為由簡單的堤壩在選定圍觀測的趨勢和嵴處有時(shí)垂直的線。 這樣的程序通常涉及到簡單的角度測量或?qū)R (補(bǔ)充測量裝置)沿頂水平位移,以確定和高程確定測定的垂直位移的水準(zhǔn)。即使有了這種監(jiān)控過程 ,很有必要延長平整一些距離超出支臺。所述的替代方法,包括結(jié)算壓力表,軟管平整的裝置使用,或者阻。結(jié)構(gòu)穩(wěn)定評估可能需要通過調(diào)查的整個(gè)生命周期的一個(gè)項(xiàng)目 ,跨越幾十年來,在許多情況下。早期規(guī)劃階段,期間的一個(gè)項(xiàng)目,綜合監(jiān)測計(jì)劃應(yīng)開發(fā)既考慮檢驗(yàn)要求在一個(gè)項(xiàng)目的生活周期,目標(biāo)取消重復(fù)和冗余的調(diào)查能最大程度的可能。在最初的設(shè)計(jì)和現(xiàn)代階段的一個(gè)項(xiàng)目 ,參考點(diǎn)應(yīng)永久地區(qū),位于有利于周期監(jiān)測調(diào)查的性能。在施工過程中,應(yīng)樹立固定監(jiān)測點(diǎn)的結(jié)構(gòu)上的呼喚在分綜合監(jiān)測計(jì)劃?！渡熊嚒稵heTrainOfLife不久以前，我讀了一本書。書中把人生比作一次旅行。人生一世，就好比是一次搭車旅行，要經(jīng)歷無

1.Notlongago,Ireadabook,inwhichaman ’slifewascomparedtoajourney.Thelifeofamanisjustlikeahitchhiking，during數(shù)次上車、下車;時(shí)常有事故發(fā)生;有時(shí)是意外驚喜，有時(shí)卻是刻骨銘心的悲傷??降生人世，我們就坐上了生命列車。我們以為我們最先見到的那兩個(gè)人------我們的父母，會在人生旅途中一直陪伴著我們。很遺憾，事實(shí)并非如此。他們會在某個(gè)車站下車，留下我們，孤獨(dú)無助。他們的愛、他們的情、他們不可替代的陪伴，再也無從尋找。盡管如此，還會有其他人上車。他們當(dāng)中的一些人將對我們有著特殊的意義。他們之中有我們的兄弟姐妹,有我們的親朋好友。我們還將會體驗(yàn)千古不朽的愛情故事。坐同一班車的人當(dāng)中，

whichmanytimeswegoupanddown.Nowandthenthingswillhappenaccidently,someofwhicharetobeunexpectedexcitement，whilesomeheart-breakingsorrows.Whenfirstembracedtheworld，wearealreadyonthetrainoflife.Wetakeitforgrantedthatthefirsttwopersons,ourparents,whomweareencounteredwith,willaccompanyusalltheway.Sadly，thingsdonotgoonaswethought.Ourparentswillgetoffthetrainatacertainstation，leavingus,bereftandhelpless.Theirloveandemotiontousandtheirirreplaceablecompanycanbefoundinnowhere.However，therewillbesomebodyelsewhowillgetonthetrain.Someofthemwillhavespecialmeaningtous.Someofthemmaybeoursiblings,relativesandfriends,andwewillalso有的輕松旅行。有的卻帶著深深的悲哀??還有的,在列車上四處奔忙，隨時(shí)準(zhǔn)備幫助有需要的人??很多人下車后，其他旅客對他們的回憶歷久彌新??但是，也有一些人，當(dāng)他們離開座位時(shí)，卻沒有人察覺。有時(shí)候，對你來說情深義重的旅伴卻坐到了另一節(jié)車廂。你只得遠(yuǎn)離他，繼續(xù)你的旅程。11.當(dāng)然，在旅途中，你也可以搖搖晃晃地穿過自己的車廂，去別的車廂找他??可惜，你再也無法坐在他身旁，因?yàn)檫@個(gè)位置已經(jīng)讓別人給占了?...沒關(guān)系。旅途充滿挑戰(zhàn)、夢想、希望、離

expereincetheimperishablelove.Someofourtravellingcompanionsarequitelight-heartedontheway.Whilesomemaybearimmensesorrow.Stillsome,backandforth,arereadytoholdouttheirhandsforotherswhoneedhelp.Somepeoplealightoffthetrain,yettheyarestillkeptinthemindoftheotherpassengersforlong;some,totheopposite,leavetheirseatswithoutbeingnoticed.