有關隧道方面外文文獻與翻譯

Aconvection-conductionmodelconditionsinsurroundingrockapermafrostregionsHEChunxiong(何雄)，KeyofFrozenSoilGeocryology,ChineseAcademyofLanzhouofAppliedUniversityofTechnology,China)WU吳汪ZHULinnan(朱林楠keyofFrozenSoilChineseAcademyofLanzhouChina)ReceivedFebruary8,Abstractonanalysesoffundamentalhydrogeologicalconditionsofinthecombinedmodelforflowinfieldinhasbeenconstructed.thetemperatureinthe2hasnumerically.resultsinagreementwiththebasedinconditionsofsirpressure,windhydrogeologyengineeringgeology,betweenonofthetunnelwallandtheexitofthehasthefreeze-thawconditionsatDabanshanwhichnowconstructionisKeywords:incoldheatexchangeconduction,AofhighwayrailwaytunnelsbeeninregionsneighboringinChina.thethermal

conditionsaftertunnelwasexcavatedsurroundingwallrocktheheavingcausedtolinerseepingwatericewhichwithtransportation.SimilarproblemsthefreezingdamageinthetunnelsappearedinlikeRussia,Japanitispredictfreeze-thawconditionsinthesurroundingrockprovideabasisforthedesign，maintenanceofnewincoldregions.Manytunnels，inregionsortheirneighbouringareas，throughthebeneathpermafrostbase.Aftera，theoriginalthermodynamicalconditionsinthawreplacedmainlybyairconnectionswithouttheheatconditionsprincipallybyofflowinthetunnel，thecoefficientsofconvectiveheattransferwall，geothermalheat.Inordertopredictfreezeandconditionsofwallof，theaxialvariationsofairtemperatureandcoefficientsofconvectivetransfer,Lunardinidiscussedconditionstheapproximateformulaeobtainedinofoutsidecircularwithof.Wetheconditionsofatunnelwallsimilarlytheperiodicchangesofthetemperature.Infact，thetemperaturesofthesurroundingwallaffectotherfindvariationstheinfurthermore，isdifficulttoquantifyofconvectiveexchangeattheofwall.Thereforeitisnottodefineonofthetunnelwallaccordingtooutsideaircombineflowconvectiveheatex-changeheatconductioninthesurroundingrockmaterialinto，theconditionsofrockmaterialinconditionsofair，pressure，windatentryexitofthetheconditionsofgeology.Mathematical

Inordertoconstructappropriatemodel,weneedtheinsitufundamentalconditionsaba-sisusesceneofDabanshanDabanshanisonthefromofRiver,atanof3754.78-3m,withof1530analignmentfromsouthwesttonortheast.tunnelrunsfromthesouthwesttheSincemonthly-averagetemperatureisbeneathforattunneltheconstructionwouldforseveral，therockmaterialswouldbecomeduringtheconstructionconcludepatternofflowwouldmainlydominantwindspeedat，andofthetemperaturebetweentheinsideoutsideoftunnelwouldbe.Sincedominantwindnortheastatinwinter,airinthewouldgotoentry.thewindtrendisinsummer,pressuretheoftheexittheflowinthetunnelwouldbefromthesincespeedatsiteislowwecouldthatflowwouldbeprincipally，simplifytheto，thatflowaretheaxisofthetunnel，Ignoringinfluenceofaironthespeedofairflow,obtainthefollowingequation:

wherexaretimeandcoordinates;Uandspeeds;Tistemperature;is，pressuredividedbydensity);vair;aofLtheofRistheequivalentoftunnelDtheoftimeaftertheconstruction;，S(t),S(t)thawedpartsinrockfrespectively;

f

,

u

Cf

u

thermalconductivitiesvolumetricthermalcapacitiesinfrozenandthawedpartsrespectively;(x,(t)phasechangefront;Lhheatlatentoffreezingwater;Tocriticalfreezingof(assumeTo=℃).2forsolvingWefirstconcerningatthattheofthesurroundingrockdoesaffectspeedofconcerningthespeedofairflow,andthensolveeveryelapse.2.1usedfortheSincefirstthreein(1)thesecond

byxthethirdequationbyr.Afterpreliminaryobtainfollowingellipticconcerningp:in(1)usingthefollowingprocedures:(i)Assumefor，V0;(ii)substituting，V0into(2)，(2)，weobtainp0;(iii)solvingfirstsecond，U0，(iv)thefirstthirdof(1)，U2，V2;(v)themomentum-averageofv1andU2weobtainnewU0，returnto(ii);(vi)aboveuntildisparityofthosesolutionsiniterationsissufficientlysmallissatisfiedweofp0V0asinitialforelapseconcerning2.2EntireusedforsolvingmentionedthetemperaturefieldofrocktheairflowaffectThusoftunneltheboundaryoffieldintheboundaryoffieldinairflowitisdifficultseparatelyidentifythetemperaturewallindependentlyconcerningthetemperatureofairflowthoseconcerningofthe.Inordertowiththissimultaneouslyofbasedonfactthatthetunnelwallsurfacebothequal.Weshouldinthephasewhileconcerningthetemperatureofrockthewhilesolvingofairflow,onlyneedtorelativeatwall.Thefor

thewithphasesamein2.3DeterminationofboundaryoftheUsingp=H，calculatepHairusing

PwhereTisabsolutetemperature，andGthehumidityconstantofLettingC

P

becapacitywithfixedpressure,thermalconductivity，dynamicofcalculatetheusingformulasａ

CP

and

.Thethermalofrockfromtunnel2.3.2oftheconditionsobservedaveragewindspeedtheexitasboundaryconditionsofwind，andchoosethe(that，theofthewindtrend)and

pkLd)/[5]theof(thatexitofthedominant)wherektheofresistancealongthetunnelwall,d=2R，andvistheaverageWeapproximateTbythesinethethesceneprovideasuitableboundarybasedthepositionofthegeothermalofthawrockbeneathpermafrostbase.3Asimulatedthethemethodmentionedabove，welawofinthewiththeattheentryexitofNo.2thatthesimulatedresultsaretothedataTheXiluoqiNo.2locatedtheinpassesthroughbeneathpermafrostbase.Ithasaof

160fromnorthwesttowiththeofinthenorthwest，andelevation700Thedominantwindinthefromtowithamaximumspeedofm/sandminimummonthly-averagespeedof1.7.Basedthedataobserved，approximatesinelawofwithyearlyaveragesof，℃of℃17.6respectively.Thediameteris5.8mtheresistantcoefficientthetunnelwalliseffectofthermalparameteroftheonairmuchthanthatofwindspeed，temperaturetheexitwereferdataobservedinDabanshanTunnelforthethermalparameters.1thesimulatedairtemperatureinsideatentryoftunnelwithdata.Wethatisthan0`Cfromthe2showsacomparisonofobservedmonthly-average(distancegreater100fromentryexit)tunnel.Wethattheisthesame，themainreasonfortheistheerrorsthatfromvaryingatentryexit;,monthly-averagetemperatureofnotforJulyfor4Predictionoffreeze-thawconditionsforDabanshanTunnel4.1Thermalparameterandtheelevationof800mtheyearly-averageairtemperatureof-3℃,we

ddcalculatetheairp=0.774kg/m

.SincesteamIntheair,wechoosethethermalcapacitywithfixedofair/(0),heatp

W/(0C)thedynamic

9.218

).Aftercalculationthethermala=1

2

/skinematic，

2

/sConsideringthattheofautomobilesisthatoftheauto-mobilespassthroughtunnellowspeedweignorecomingfrommovementautomobilesinofair.Weconsiderrockaandchoosecavity

d

/

3

ofwaterwaterW=3%W=1%,thermal

1.9W/.

c

,

f

2.0/

o

capacity0.8kJ/.V

candCf

w)uu11

dtodatathesitemaximummonthly-averagespeedisabout3.5m/s，theminimummonthly-averagespeedis2m/s.Weapproximatethewindspeedattheexitv(t)to

m/s,tisinmonth.ThespeedinrU(0xr)U()R

),(0xr)TheoftemperatureTaresettobewheref(x)fromthepermafrostofdo-mainofsolutionassumethatthe3%，theairoutsidetunnelis

0

，amplitudeis

B=120foroffirstsolveR=Rothefirsttypeofthatisassumethat3%

0

findthat,theheatflowwillhaveinrangeofradiusbetween5andinthesurroundingthewillbecooleritwillaffectedbygeothermalappoximatelythattheboundaryR=Roisthesecondtypeofthatis，thatfromcalculationtotheoffirstexcavationthefirstofboundaryvalue,isthegradientonR=RoofConsideringsurroundingrocktoduringperiodofconstruction，calculatefromJanuaryanditerateofunderboundary.lettheboundaryvarysolvebycanbeprovedthesolutionwillnottheofaftermanytimeelapses).4.2CalculatedresultsFigures3and4showtheofmonthly-averagetemperaturesonofwallalongwiththevariationsatentry.Figs.5and6thepermafrostbeginstoformandthethawedafterpermafrostformeddifferentsections.

4.3Preliminaryconclusionthermalparametersabove,wefollowingpreliminary1)Theonthesurfacewallofapproximatelytoairatentryexit.Itwarmerthecoldandcoolerduringseasonintheinternal100mfromtheexit)ofthe.1thattheinternalonofthetunnelis℃higherinDecember,1℃higherinMarchOctober,1.6lowerinJuneandandlowerinJulythetemperatureattheentryInotherinfernaltemperatureonofwallapproximatelythetemperatureatentryexit.2)Sinceitisbythegeothermalintheinternalsurrounding，inthecentralofthe

onofwalldecreasesand1℃thatatentryexit.3thethatthesurroundingiscompact,withoutaamountalayer(asPUwithofmand

=0.0216℃，FBTwithofmconductivity=0.0517W/m℃，inyeartunnelconstruction，thesurroundingrockwillbegintoformpermafrostintherangeofmfromexitfirstsecondyearthewilltoformpermafrostintheof40andfromtheentryexit.Incentral，fromentrywillformtheeighthNeartheofthe，permafrostwillappearintheyears.Duringfirstsecondafterpermafrostformed，maximumofannualdepth(especiallythecentralpartoftherocksection)thereafteritdecreasesTheofannualthawedwillstablethe19-20thyearswillremaininof2-34)Ifpermafrostentirelyinsurrounding，thepermafrostwillprovidebefavourablefor.However,intheprocessofconstructionlotofinsomeofwillinseepingwaterresultinginthelinerworkwillbereportedelsewhere.

嚴寒地隧道圍巖凍狀況分的導熱與對換熱模何春雄吳紫汪朱林楠（中國科學院寒區(qū)旱區(qū)環(huán)境與工程研究所凍土工程國家重點實驗室）（華南理工大學應用數學系）摘

要通過對嚴寒地區(qū)隧道現場基本氣象條件的分析立了隧道內空氣與圍巖對流換熱及固體導熱的綜合模型;此模型對大興安嶺西羅奇2號隧道的洞內氣溫分布進行了模擬計算，結果與實測值基本一致;分析預報了正在開鑿的祁連山區(qū)大坂山隧道開通運營后洞內溫度及圍巖凍結、融化狀況關鍵詞

嚴寒地區(qū)隧道

導熱與對流換熱

凍結與融化在我國多年凍土分布及鄰近地區(qū)，修筑了公路和鐵路隧道幾十座由于隧道開通后洞內水熱條件的變;，普遍引起洞內圍巖凍結，造成對襯砌層的凍脹破壞以及洞內滲水凍結成冰凌等，嚴重影響了正常交通類似隧道凍害問題同樣出現在其他國家（蘇聯、挪威、日本等)的寒冷地區(qū)如何預測分析隧道開挖后圍巖的凍結狀況為嚴寒地區(qū)隧道建設的設計施工及維護提供依據這是一個亟待解決的重要課題.在多年凍土及其臨近地區(qū)修筑的隧道數除進出口部分外從多年凍土下限以下巖層穿過隧道貫通后，圍巖內原有的穩(wěn)定熱力學條件遭到破壞，代之以阻斷熱輻射、開放通風對流為特征的新的熱力系統(tǒng).隧道開通運營后，圍巖的凍融特性將主要由流經洞內的氣流的溫度、速度、氣—固交界面的換熱以及地熱梯度所確定.為分析預測隧道開通后圍巖的凍融特性Lu-nardini借用Shamsundar究圓形制冷管周圍土體凍融特性時所得的近似公式，討論過圍巖的凍融特性.我們也曾就壁面溫度隨氣溫周期性變化的情況，分析計算了隧道圍巖的溫度場實際情況下，圍巖與氣體的溫度場相互作用，隧道內氣體溫度的變化規(guī)律無法預先知道，加之洞壁表面的換熱系數在技術上很難測定而由氣溫的變化確定壁面溫度的變化難以實本文通過氣一固禍合的辦法，把氣體、固體的換熱和導熱作為整體來處理從洞口氣溫風速和空氣濕度壓力及圍巖的水熱物理參數等基本數據出發(fā)，計算出圍巖的溫度場.

1學模型為確定合適的數學模型，須以現場的基本情況為依據.這里我們以青海祁連山區(qū)大坂山公路隧道的基本情況為背景來加以說明.大山隧道位于西寧一張業(yè)公路大河以南，海拔3754.78~3801.23，全長m道近西南—東北走向.由于大坂山地區(qū)隧道施工現場平均氣溫為負溫的時間每年約長個月之施工時間持續(xù)數年圍巖在施土過程中己經預冷所以隧道開通運營后洞內氣體流動的形態(tài)主要由進出口的主導風速所確定受洞內圍巖地溫與洞外氣溫的溫度壓差的影響較小季祁連山區(qū)盛行西北風將從隧道出曰流向進口端，夏季雖然祁連山區(qū)盛行東偏南風但考慮到洞口兩端氣壓差溫度壓差以及進出口地形等因素，洞內氣流仍將由出口北端流向進口端另外，由于現場年平均風速不大，可以認為洞內氣體將以層流為主基于以上基本情況，我們將隧道簡化成圓筒，并認為氣流、溫度等關十隧道中心線軸對稱，忽略氣體溫度的變化對其流速的影響，可有如下的方程其中t為時間x為軸向坐標r為徑向坐標U,V分別為軸向和徑向速度T為溫度，有效壓力(即空氣壓力與空氣密度之比少，V為氣運動粘性系數，a空氣的導溫系數L隧道長度隧道的當量半徑D為時間長(t)f

()別為圍巖的凍區(qū)域u

f

分別為凍狀態(tài)下的熱傳導系數,uf

u分別為凍、融狀態(tài)下的體積熱容量，,t為凍、融相變界面,To為巖石凍結臨界溫度(里具體計算時取

C)，L為水的相變潛熱h2求解過程由方程(知，圍巖的溫度的高低不影響氣體的流動速度，所以我們可先解出速度，再解溫度.2.1連續(xù)性方程和動量方程的求解由于方程((1)的前3個方程不是相互獨立的，通過將動量方程分別對和求導，經整理化簡，我們得到關于壓力P如下橢圓型方程:于是，對方程(1)中的連續(xù)性方程和動量方程的求解，我們按如下步驟進行:設定速U

0

,

0

;(U入方程并求解，得P0聯立方程(的第一個和第二個方程，解得一組U1,1聯立方程((1)的第一個和第三個方程，解得一組U

2

,

2

;對((3)得到的速度進行動量平均,得新U

0

,

0

返回(2);按上述方法進行迭代到前后兩次的速度值之差足夠小.0,U,V0為本時段的解,一時段求解時以此作為迭代初值2.2能量方程的整體解法如前所述圍巖與空氣的溫度場相互作用壁面既是氣體溫度場的邊界又是固體溫度場的邊界壁面的溫度值難以確定我們無法分別獨立地求解隧道內的氣體溫度場和圍巖溫度為克服這一困難，我們利用在洞壁表面上，固體溫度等于氣體溫度這一事實隧道內氣體的溫度和圍巖內固體的溫度放在一起求

解，這樣壁面溫度將作為末知量被解出來只是需要注意兩點:解流體溫度場時不考慮相變和解固體溫度時沒有對流項;在洞壁表面上方程系數的光滑化另外，帶相變的溫度場的算法與文獻[相同2.3參數及初邊值的確定熱參數的確定方法用計算出海拔高度為的隧道現場的大氣壓強，再

P

計算出現場空氣密度，其中T現場大氣的年平均絕對溫度為空氣的氣體常數記定壓比熱C,導熱系數，空氣的動力粘性系數P為ａ

CP

和

計算空氣的導溫系數和運動粘性系數.圍巖的熱物理參數則由現場采樣測定.初邊值的確定方法:洞曰風速取為現場觀測的各月平均風速取卞導風進曰的相對有效氣壓為，主導風出口的氣壓則取為pkL/d

2

/2

[5]

，這里k隧道內的沿程阻力系數，L為隧道長度，為隧道端面的當量直徑，為進口端面軸向平均速度.進出口氣溫年變化規(guī)律由現場觀測資料，用正弦曲線擬合，圍巖內計算區(qū)域的邊界按現場多年凍土下限和地熱梯度確定出適當的溫度值或溫度梯度3計算實例按以上所述的模型及計算方法們對大興安嶺西羅奇號隧道內氣溫隨洞曰外氣溫變化的規(guī)律進行了模擬計算驗證，所得結果與實測值[6]相比較基本規(guī)律一致.西羅奇2號隧道是位十東北嫩林線的一座非多年凍土單線鐵路隧道，全長1160,隧道近西北一東南向，高洞口位于西北向，冬季隧道主導風向為西北風.洞口海拔高度約為700月平均最高風速約為低風速約為1.7m/s.根據現場觀測資料，我們將進出口氣溫擬合為年平均分別為-5

0

和-

0

變化振幅分別為

0

和

0

的正弦曲

線.道的當量直徑為5.8沿程阻力系數取為由于圍巖的熱物理參數對計算洞內氣溫的影響遠比洞口的風速壓力及氣溫的影響小得多我們這里參考使用了大坂山隧道的資料.圖1出了洞口及洞內年平均氣溫的計算值與觀測值比較的情況從進口到出口，兩值之差都小于0.2

0

圖出了洞內(距進出口l00m以上月平均氣溫的計算值與觀測值比較的情況可以看出溫度變化的基本規(guī)律完全一致造成兩值之差的主要原因是洞口氣溫年變化規(guī)律之正弦曲線的擬合誤差，特別是年隧道現場月平均最高氣溫不是在7份，而是在8月份.4對大坂山隧道洞內壁溫及圍巖凍結狀況的分析預測4.1參數及初邊值按大坂山隧道的高度值3800m和年平均氣

0

，我們算得空氣密度

0.774kg/3比[7]kJ/m導熱系數