外文資料翻譯柔弱巖石上短距離隧道的動(dòng)態(tài)施工力學(xué)的研究

1、畢業(yè)設(shè)計(jì)外文資料翻譯題 目 柔弱巖石上短距離隧道 的動(dòng)態(tài)施工力學(xué)的研究 學(xué) 院 土木建筑學(xué)院 專(zhuān) 業(yè) 土木工程 班 級(jí) 土木 學(xué) 生 二一 一 年 三 月 四 日modern applied science vol. 4, no. 6; june 2010柔弱巖石上短距離隧道的動(dòng)態(tài)施工力學(xué)的研究吳恒斌(通訊作者)重慶長(zhǎng)江三峽大學(xué)土木工程系 中國(guó)重慶萬(wàn)州市二段沙龍路780號(hào)電子郵件:hbw8456賀云翔重慶長(zhǎng)江三峽大學(xué)土木工程系 中國(guó)重慶萬(wàn)州市二段沙龍路780號(hào)郭良松聊城建宇工程有限公司中國(guó)聊城252000摘要基于建設(shè)理論的新奧地利方法(nam),依賴(lài)在柔弱巖石的短距離隧道工程,通過(guò)構(gòu)建數(shù)學(xué)模型

2、并進(jìn)行了三維彈塑性有限元法的建構(gòu)過(guò)程中,雙邊墻的施工方法。分析隧道周?chē)恍y(cè)量點(diǎn)位移的變化和隧道開(kāi)挖和洞室群圍巖的穩(wěn)定性,通過(guò)分析地表塌陷、承擔(dān)的力量支護(hù)結(jié)構(gòu)與塑性區(qū)。結(jié)果表明,上述構(gòu)造法是合理的在以后的隧道開(kāi)挖，地表沉陷，隧道變形與早期隧道開(kāi)挖的影響比較明顯。關(guān)鍵詞:柔弱的巖石、小距離隧道、動(dòng)態(tài)建筑機(jī)械、數(shù)值模擬1介紹過(guò)程的開(kāi)挖與支護(hù)隧道是一項(xiàng)復(fù)雜的機(jī)械加工過(guò)程，施工過(guò)程之間的差別，開(kāi)挖順序，支持的時(shí)間大為影響工程結(jié)構(gòu)系統(tǒng)(she et al., 2006).的力學(xué)效應(yīng)由于周?chē)鷰r石條件的復(fù)雜性普通的類(lèi)似項(xiàng)目在柔弱巖石特別是小距離隧道工程的復(fù)雜連接中是不夠的，因此,根據(jù)在施工過(guò)程中各負(fù)荷情況，

3、在不同的圍巖中有必要進(jìn)行機(jī)械模擬和分析在柔弱巖石隧道襯砌方面的研究，sun et al. (1994)考慮了時(shí)空效應(yīng)隧道挖掘表面建立三維數(shù)模型。cheng et al. (1997) 分析了力學(xué)機(jī)制和flac隧道襯里復(fù)雜的承載能力，得到一些有用的結(jié)論。jin et al. (1996) 應(yīng)用非線性粘彈性理論進(jìn)行了三維有限元模擬圓隧道開(kāi)挖過(guò)程。karakus(2007)闡述了由平面應(yīng)變分析造成的三個(gè)尺寸挖掘影響。因?yàn)闀r(shí)空效應(yīng)還不能全部體現(xiàn),許多研究人員進(jìn)行了三維彈塑性有限元法和隧道開(kāi)挖的彈塑性分析(an, 1994, xiao, 2000 & zhu et al. 1996)。在小距離隧道方面的

4、研究liu et al. (2000)在中國(guó)第一個(gè)超級(jí)短距離隧道進(jìn)行的測(cè)試中距離隧道在中國(guó)。wan et al. (2000) 取得了具體小距離隧道的概念。jin et al. (2004) 通過(guò)數(shù)值模擬分析討論了施工方法的適應(yīng)性。yan et al.分析了在不同施工方案中支撐的機(jī)械特性和變形規(guī)則。liu et al。(2006)介紹了短距離8車(chē)道公路隧道的設(shè)計(jì)方案。大多數(shù)上述研究的目的分別是柔弱巖石隧道的建筑特征和小距離隧道建設(shè)方案的比較和選擇由于很少做結(jié)合兩方面的討論，因此，有必要研究小距離柔弱巖石動(dòng)態(tài)施工特點(diǎn)。2工程概況2.1工程地質(zhì)地質(zhì)調(diào)查顯示,底部隧道主要打通的是下面的基礎(chǔ)，主要是泥

5、巖，砂巖。撞擊地層的方向交叉降至85。隧道、地層傾角約有9,結(jié)合層巖石很普通，巖石的等級(jí)是五級(jí)。地下水很匱乏，隧道中水的主要形式是潮濕或滴下來(lái)。鋼筋混凝土的極限抗壓強(qiáng)度= 4.59mpa，完整性因素kv=0.65,k1 = 0.2,k2 = 0.3,k3 = 0,工程量清單計(jì)價(jià)= 219。砂巖鋼筋混凝土的極限抗壓強(qiáng)度=2549mpa,完整因素kv=0.64,k1= 0.5,k2 = 0.2,k3 = 0,工程量清單計(jì)價(jià)= 319。地質(zhì)構(gòu)造的表面非常發(fā)達(dá)，巖體極其支離破碎,而且塊強(qiáng)度不夠強(qiáng)。所以它屬于典型的類(lèi)柔弱的巖石。2.2工程施工方法。雙墻指導(dǎo)施工方法中的配角,以先進(jìn)的小管為了減少隧道施工對(duì)

6、高速公路經(jīng)營(yíng)管理的影響，確保隧道建設(shè)的安全雙邊墻施工方法以先進(jìn)的小管作為支撐角色引導(dǎo)。先進(jìn)小管的外半徑是42mm,長(zhǎng)度是四十厘米。在施工過(guò)程中,開(kāi)挖的長(zhǎng)度是受到嚴(yán)格控制的，主要支撐每隔四米設(shè)置一個(gè)。30厘米厚的封閉鋼筋混凝土環(huán)被襄鑄在第二內(nèi)襯和主要支撐之間。螺栓的形式是空心注漿和quincunx布局、直徑和長(zhǎng)度是作為軌道后,4.5米、垂直和周向所在分別是200厘米和80厘米第二內(nèi)襯和主要支撐被澆鑄成28厘米厚c20模型和60厘米厚c25厚鋼筋混凝土模型3數(shù)值模型隧道長(zhǎng)度是選為仿真模型,該模型被選為20米長(zhǎng)，該模型有21850個(gè)小構(gòu)件其中螺栓有3850構(gòu)件(圖1)。隧道圍巖被認(rèn)為是彈塑性材料。因

7、為支撐結(jié)構(gòu)的力學(xué)性能優(yōu)于圍巖,所以它可以被看作是彈性材料。鋼拱的影響在架子上和先進(jìn)的小管?chē)娚浠炷量梢阅M使用等效的方法。tab.1是基本力學(xué)參數(shù)的物質(zhì)。為確保計(jì)算的準(zhǔn)確性該模型維度可以設(shè)為:左和右都長(zhǎng)50米垂直于地球表面下為50米。4進(jìn)行結(jié)果分析4.1分析地表沉陷,地面沉降應(yīng)嚴(yán)格控制,以確保隧道施工中高速公路運(yùn)營(yíng)管理的安全隧道施工。從圖2,圖像的地表沉陷隧道開(kāi)挖完成后,它可以看出地表沉陷對(duì)稱(chēng)分布近似在雙線隧道、展示w的形狀。早期隧道拱頂端地面沉降規(guī)模最大，沉降值為5.31mm，這是由于早期隧道開(kāi)挖完成以后，后期隧道建設(shè)造成的擾動(dòng)，這和現(xiàn)場(chǎng)監(jiān)測(cè)的信息和數(shù)據(jù)規(guī)則是一致的。后期隧道拱頂端地面沉降量

8、是5.31mm。在隧道中軸線附近的地表沉降小于兩個(gè)隧道拱頂所在的地表沉降，沉降值只有2.87mm?？梢詮膱D二中得出的結(jié)論是隧道開(kāi)挖的影響對(duì)地表沉陷趨于穩(wěn)定的距離范圍是中軸線直徑的3.5倍,也揭示了該仿真模型的選擇范圍是沒(méi)有錯(cuò)誤的4.2巷道變形分析如圖3所示,后期隧道拱頂端的垂直地表沉降是7.20mm,最大的垂直地表沉降值出現(xiàn)在早期隧道拱頂端。因?yàn)橹蟮乃淼朗┕ば?是7.33mm。與一般的大垮較淺深度的隧道地表沉降的現(xiàn)場(chǎng)測(cè)量值相比，頂部處理的沉降值略小?？梢约俣?先進(jìn)的小管在加固巖石上發(fā)揮了很大作用，逆變值相對(duì)較大，早期的隧道和后期的隧道分別是9.87mm 9.85mm。分析結(jié)果表明,隧道圍巖的

9、垂直缺陷值滿(mǎn)足施工的需要、初始參數(shù)設(shè)定隧道結(jié)構(gòu)是合理的。4.3支撐承載力的分析如圖4所示,出現(xiàn)在拱腳的最大受力值是7.31mpa.。在施工過(guò)程中應(yīng)該加強(qiáng)現(xiàn)場(chǎng)監(jiān)測(cè)的力度。從圖五中以發(fā)現(xiàn)在拱頂和拱腳位置的螺栓的軸向力更大。最大值是42.56kn，滿(mǎn)足抗拉強(qiáng)度要求。螺栓軸向力最主要的分布形式是“凸肚”式。符合螺栓軸向力在柔弱巖石上的分布格局。處在拱腳位置的少量螺栓時(shí)處于壓縮狀態(tài)的。可能由于主要支撐的剛度太大，結(jié)果是減少了拱腳的變形和反演脹的現(xiàn)象。從圖六中可以看出第二內(nèi)襯的應(yīng)力規(guī)律和主要支撐是相似的，邊墻的壓力要大于其他部位最大應(yīng)力值是0.2mpa滿(mǎn)足在中國(guó)要求的標(biāo)準(zhǔn)4.4塑性區(qū)分析從圖7,便會(huì)發(fā)現(xiàn),

10、塑性區(qū)主要分布在拱頂、拱門(mén)、拱門(mén)腳的位置，這也許是由于由雙邊墻施工方法造成的過(guò)多的應(yīng)力進(jìn)入了側(cè)墻 。先進(jìn)的小管的支持、初期支護(hù),其次內(nèi)襯可以預(yù)防塑性區(qū)進(jìn)一步擴(kuò)張,塑性區(qū)深度,不會(huì)超過(guò)一半的隧道寬度,而在允許范圍內(nèi)。所以隧道圍巖塑性區(qū)的發(fā)隧洞的穩(wěn)定性隧道仍然情況穩(wěn)定。5結(jié)論隧道地表沉陷的分布在中心軸線基礎(chǔ)上,顯示w型,由于解決方案主要集中在3.5倍中心軸線的直徑范圍內(nèi)，先進(jìn)小管的支持能夠加固圍巖有效防止兩個(gè)隧道之間塑性區(qū)的擴(kuò)張。從圍巖結(jié)構(gòu)的變形結(jié)果可以看到后期隧道開(kāi)挖地表沉陷與隧道變形對(duì)早期的隧道的影響大于早期隧道開(kāi)挖對(duì)后期隧道的影響。對(duì)上述結(jié)果進(jìn)行分析地面沉降、隧道周邊的垂直位移，支撐的承載力

11、和塑性區(qū)雙邊墻建設(shè)方案是合理的。參考文獻(xiàn)【中國(guó)巖石力學(xué)與工程】（3，623-629）三維彈塑性數(shù)值模擬軟圍巖位移建設(shè)的進(jìn)程。佘健，何川（2006年）?！編r土力學(xué)】（4，20-33。）力學(xué)模擬及軟弱巖石中的行為分析，興建一條隧道開(kāi)放。孫軍，朱合華（1994年）?！編r土力學(xué)】（4，327-336）數(shù)值分析大型復(fù)雜的非線性變形機(jī)制及隧道襯砌。鄭華，孫軍（1997年）?！編r石和土壤力學(xué)】（3，193-200）模擬三維隧道挖掘。靳鳳年、錢(qián)七虎（1996年）?！舅淼琅c地下空間技術(shù)】（22，47-56）評(píng)價(jià)隧道的二維平面應(yīng)變有限元分析的影響及三維方法核算。m.karakus（2007年）。【中國(guó)民建工程】（

12、5，87-91）三維有限元的軟土蠕變對(duì)隧道的影響。安官峰(2001年）?！局袊?guó)巖土工程學(xué)報(bào)】（4，421-425)三維數(shù)值模型的地下洞室施工過(guò)程。肖明（2000年）?！臼┕ちW(xué)】（北京科學(xué)出版社）周邊復(fù)雜條件下圍巖穩(wěn)定性和巖石動(dòng)態(tài)。朱煒沉，何滿(mǎn)潮（1996年）【巖土力學(xué)】（5，590-594）實(shí)驗(yàn)研究機(jī)械特性和小間距隧道。劉顏青，韓世航，盧汝綏，馬榮田（2000年）?！靖咚俟贰浚?，55-58）討論環(huán)境對(duì)小間距研究長(zhǎng)隧道的影響。萬(wàn)明富（2000年）?！舅淼腊踩こ屉s志】（2，63-68）開(kāi)挖小距離隧道的方法分析。金曉廣，劉煒，秦峰，汪劍華（2004年）。【中國(guó)巖石工程力學(xué)】（3，572-57

13、7）對(duì)軟巖施工特性和動(dòng)態(tài)行為的研究。嚴(yán)琦祥，何川，姚勇（2006年）?！靖咚俟贰浚?2，217）大跨公路隧道結(jié)構(gòu)設(shè)計(jì)與分析。劉紅州，陳三佳（2006年） 圖1 有限元分析模型 圖2 地表沉陷圖表 圖3 圍巖的垂直位移（mm）圖4 主要支撐的等量壓力 圖5 螺栓的軸力圖圖6 次連接的等量應(yīng)力 圖7 圍巖的塑性區(qū) study on dynamic construction mechanics of small-distance tunnelin soft and weak rockshengbin wu (corresponding author)department of civil engi

14、neering, chongqing three gorge university780 erduan shalong road, wanzhou district, chongqing 404000, chinae-mail: hbw8456yunxiang hedepartment of civil engineering, chongqing three gorge university780 erduan shalong road, wanzhou district, chongqing 404000, chinaguoliang songliaocheng jianyu constr

15、uction engineering co.,ltdliaocheng 252000, chinaabstractbased on the construction theory of new austria method(nam), relyed on a tunnel project of small distance insoft and weak rocks, this paper builds the numerical model and simulates 3d finite element method elastoplasticof the construction proc

16、ess by the construction method of double-sidewalls. the displacement changes of somepoints around the tunnel are analysised with the tunnels excavation. the safety of the tunnel structure andstability of surrounding rock are estimated by analyzing the surface subsidence, forces undertaken by thesupp

17、orting structures and plastic zone. the results show that the method of construction mentioned above isreasonable, the influence of the later tunnel excavation on the surface subsidence and tunnel deformations of theearlier tunnel excavation is relatively obvious.keywords: soft and weak rocks, small

18、 distance tunnel, dynamic construction mechanics, numerical simulation1. introductionthe excavation and supporting process of tunnel is a complicated mechanical process, the differences ofconstruction process, excavation sequence and supporting time greatly influence on the mechanics effects ofengin

19、eering structure systematic(she et al., 2006). because of the complexity of the condition of surroundingrock, the ordinary analogy of projects is not enough in the complex lining in soft and weak rocks especially inthe tunnel engineering with small distance, so its necessary to conduct the mechanica

20、l simulating and analyzingin different surrounding rock characters according to the different forcing stages in each load case duringconstruction processes.in the aspect of the research on the tunnel lining in soft and weak rocks, sun et al. (1994) builded the threedimension model considering the ti

21、me-space effect of tunnel excavating surface. cheng et al. (1997) analyzedthe mechanical mechanism and carrying capacity of complex lining for tunnels with flac, and got some usefulconclusions. jin et al. (1996) conducted three dimension fem (finite element method) numerical simulation tothe excavat

22、ion processes of circle tunnel using the nonlinear viscoelastic theory. karakus(2007)elaborated threedimension excavating effect caused by plane strain analyses. because the time-space effect could not be fullyreflected, many researchers conducted three dimension fem elastoplastic and visco-elastopl

23、astic analyses totunnel excavation(an, 1994, xiao, 2000 & zhu et al., 1996).in the aspect of the research in the tunnel ofsmall distance, liu et al. (2000) carried out the tests on zhaobaoshan tunnel, which is the first super smalldistance tunnel in china. wan et al. (2000) made specifically the con

24、cept of small distance tunnel. jin et al.(2004) discussed the adaptability of the construction methods through the numerical simulating. yan et al.(2006) analyzed the mechanical characteristic and deformation rules of the supports in different constructionmethods. liu et al. (2006) introduced the de

25、sign scheme of highway tunnel of small distance with 8 lanes. mostof studies mentioned above were aimed separately at construction characters of the tunnel in soft and weak rocks117modern applied science /masand the comparison and selection of the construction schemes of small distanc

26、e tunnel. the discussioncombining the two aspects is less made, so its necessary to study the dynamic construction mechinicscharacteristic of small distance tunnel in soft and weak rocks.2. engineering general situation2.1 engineering geologythe geological survey shows that the bottom, the tunnel mo

27、stly get through, is the jurassic upper shaximiao, andthe underlying bedrock is the interbedded of mudstone and sandstone. the strike direction of the strata intersectthe tunnel axis to 85, the strata dip angle is about 9, the combination between the layers of rock is general, andthe level of rock i

28、s grade v. the groundwater is poor, and the main form of the water in tunnel is damp ordripping. the saturated uniaxial compressive strength of mudstone rc=4.59mpa, integrity factor kv=0.65,k1=0.2, k2=0.3, k3=0, bq=219. the saturated uniaxial compressive strength of sandstone rc=25.49mpa,integrity f

29、actor kv=0.64, k1=0.5, k2=0.2, k3=0, bq=319. the surface of geological structure is verydeveloped, the rock body is extremely fragmented, and the block strength is not strong. so it belongs to thetypical category of the soft and weak rocks.2.2 engineering construction methodthe double side-walls con

30、struction method is guided under the supporting role with advanced small pipe, inorder to reduce the influence of tunnel construction on the highway operations, ensure the safety of tunnelconstruction. the outside radius of advanced small pipe is 42mm, the length is 3.5m and the circumferentialspaci

31、ng is 40cm. in the construction process, the excavation length is controlled strictly, the primary support isconstructed every 4m, and the 30cm thick closed loop of steel concrete is molded between the secondly liningand primary support. the bolts are the forms of hollow grouting and quincunx layout

32、, the diameter and lengthare setted as 25mm and 4.5m, the vertical and circumferential spacing are located 200cm and 80cm apart. theprimary support and secondly lining are forms of the 28cm thick c20 shotcrete and 60cm thick c25 modelreinforced concrete.3. numericalmodelthe tunnel length in simulati

33、ng model is selected as 20m, and the model has 21850 elements, in which boltshave 3850 elements(fig.1). the tunnel surrounding rock is considered to be elastoplastic material. because themechanics characteristic of the support structure is better than the surrounding rock, so it could be regarded as

34、elastic material. the effect of steel arch shelf in shotcrete and advanced small pipe could be simulated usingequivalent method. tab.1 is the basic mechanics parameter of the material. in order to ensure the veracity ofcalculation, the model dimension can be set as : left and right are all 50m, vert

35、ical to earth surface, down is 50m.4 results analysis4.1 surface subsidence analysisthe surface subsidence should be strictly controlled, in order to ensure the safety of highway operations in thetunnel construction. from fig.2, the graph of the surface subsidence after completion of the tunnel exca

36、vation, itcan be seen that the surface subsidence is approximate symmetrical distribution on the two-lane tunnel, showingw shape. the surface subsidence in the top of the earlier tunnel vault is largest, the value is 5.31mm, which is dueto the construction disturbance caused by the later tunnel afte

37、r completion of the earlier tunnel excavation. thisis consistent with the information and data rules of on-site monitoring. the surface subsidence in the top of thelater tunnel vault is 5.31mm, the surface subsidence near the central axis line are smaller than the top of the twotunnel vaults, the va

38、lue is only 2.87mm. generally speaking, the surface subsidence can guarantee normalconstruction under the safety operation of highway. the conclusion, which could also be seen from fig.2, is thatthe impact of the tunnel excavation on surface subsidence tends to be stable in the range of the distance

39、s of 3.5times the diameter to the central axis, which also indicates the selection range of this simulation model is withinthe error.4.2 tunnel deformation analysisas can be seen from fig.3, the vertical subsidence of the later tunnel vault is 7.20mm, and the largest value ofthe vertical subsidence,

40、 which appears in the earlier tunnel vault because of the construction effect of the latertunnel, is 7.33mm. the value of crown settlement is slightly small compared with the on-site monitoring value ofthe tunnels with general shallow-depth and large-span. it can be assumed that, the advanced small

41、pipe hasplayed effectively a role of reinforcing rock. the invert heaving value is relatively large, the earlier tunnel andlater tunnel are 9.87mm, 9.85mm. the analysis indicates that the vertical deformation of the tunnel surrounding118modern applied science vol. 4, no. 6; june 2010rock meets the c

42、onstruction requirement, the initial parameters set of the tunnel structures are reasonable.4.3 analysis of forces undertaken by supportsas can be seen from fig.4, the largest value which appears in the arch foot is 7.31mpa. the on-site monitoring inthe arch foot should be strengthened in the constr

43、uction process. from fig.5, it can be found that, the axial forceof bolts is larger in the position of the vault and hance, the largest value is 42.56kn, which meets the requirementof the tensile strength. the most distribution of the bolts axial force is the form of “convex belly”, which isconsiste

44、nt with the distribution pattern of the bolt axial force in soft and weak rocks. a small amount of bolts inarch foot position are compression state, which maybe due to the stiffness of the primary support is too large,resulting in less deformation of arch foot and the phenomenon of invert heaving. a

45、s can be seen from fig.6, thestress law of the secondly lining is similar with primary support. the side-wall stress is larger than the others, thelargest value is 0.2mpa, which meets the requirement criterion in china.4.4 plastic zone analysisfrom fig.7, it can be seen that, the plastic zone is mai

46、nly distributed in the position of the vault, arch and archfoot, which is probably due to the side-walls undertaken excessive forces caused by double-sidewallsconstruction method. the supports of advanced small pipe, primary support and secondly lining can preventeffectively the further expansion of

47、 the plastic zone, the depth of plastic zone does not exceed the half of thetunnel width, which is within the allowable range. therefore the development of plastic zone of the tunnel doesnot affect significantly the stability of the tunnel, and the tunnel is still in stable condition.5. conclusionst

48、he distribution of the tunnel surface subsidence is on the central axis basis, showing w shape, and thesettlement mainly concentrated in the range of the distance of 3.5 times the diameter to the central axis. thesupport of advanced small pipe can reinforce the surrounding rock, and prevent effectiv

49、ely the expansion of theplastic zone between the two tunnels. from the deformation results of the surrounding rock, it can seen that, theinfluence of the later tunnel excavation on the surface subsidence and tunnel deformations of the earlier tunnelexcavation is larger than the earlier tunnel impact

50、s on the later tunnel. from the results analysis mentioned aboveof the surface subsidence, vertical displacement of the tunnel surrounding, undertaken forces of the supports andthe plastic zone, the construction schemes of double- sidewalls is reasonable.referencesshe jian, & he chuan. (2006). 3d el

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