外文资料翻译柔弱岩石上短距离隧道的动态施工力学的研究.doc

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1、毕业设计外文资料翻译题 目 柔弱岩石上短距离隧道 的动态施工力学的研究 学 院 土木建筑学院 专 业 土木工程 班 级 土木 学 生 二一 一 年 三 月 四 日Modern Applied Science Vol. 4, No. 6; June 2010柔弱岩石上短距离隧道的动态施工力学的研究吴恒斌(通讯作者)重庆长江三峡大学土木工程系 中国重庆万州市二段沙龙路780号电子邮件:hbw8456贺云翔重庆长江三峡大学土木工程系 中国重庆万州市二段沙龙路780号郭良松聊城建宇工程有限公司中国聊城252000摘要基于建设理论的新奥地利方法(NAM),依赖在柔弱岩石的短距离隧道工程,通过构建数学模型

2、并进行了三维弹塑性有限元法的建构过程中,双边墙的施工方法。分析隧道周围一些测量点位移的变化和隧道开挖和洞室群围岩的稳定性,通过分析地表塌陷、承担的力量支护结构与塑性区。结果表明,上述构造法是合理的在以后的隧道开挖，地表沉陷，隧道变形与早期隧道开挖的影响比较明显。关键词:柔弱的岩石、小距离隧道、动态建筑机械、数值模拟1介绍过程的开挖与支护隧道是一项复杂的机械加工过程，施工过程之间的差别，开挖顺序，支持的时间大为影响工程结构系统(SHE et al., 2006).的力学效应由于周围岩石条件的复杂性普通的类似项目在柔弱岩石特别是小距离隧道工程的复杂连接中是不够的，因此,根据在施工过程中各负荷情况，

3、在不同的围岩中有必要进行机械模拟和分析在柔弱岩石隧道衬砌方面的研究，SUN et al. (1994)考虑了时空效应隧道挖掘表面建立三维数模型。CHENG et al. (1997) 分析了力学机制和FLAC隧道衬里复杂的承载能力，得到一些有用的结论。JIN et al. (1996) 应用非线性粘弹性理论进行了三维有限元模拟圆隧道开挖过程。Karakus(2007)阐述了由平面应变分析造成的三个尺寸挖掘影响。因为时空效应还不能全部体现,许多研究人员进行了三维弹塑性有限元法和隧道开挖的弹塑性分析(AN, 1994, XIAO, 2000 & ZHU et al. 1996)。在小距离隧道方面的

4、研究LIU et al. (2000)在中国第一个超级短距离隧道进行的测试中距离隧道在中国。WAN et al. (2000) 取得了具体小距离隧道的概念。JIN et al. (2004) 通过数值模拟分析讨论了施工方法的适应性。YAN et al.分析了在不同施工方案中支撑的机械特性和变形规则。LIU et al。(2006)介绍了短距离8车道公路隧道的设计方案。大多数上述研究的目的分别是柔弱岩石隧道的建筑特征和小距离隧道建设方案的比较和选择由于很少做结合两方面的讨论，因此，有必要研究小距离柔弱岩石动态施工特点。2工程概况2.1工程地质地质调查显示,底部隧道主要打通的是下面的基础，主要是泥

5、岩，砂岩。撞击地层的方向交叉降至85。隧道、地层倾角约有9,结合层岩石很普通，岩石的等级是五级。地下水很匮乏，隧道中水的主要形式是潮湿或滴下来。钢筋混凝土的极限抗压强度= 4.59Mpa，完整性因素KV=0.65,K1 = 0.2,K2 = 0.3,K3 = 0,工程量清单计价= 219。砂岩钢筋混凝土的极限抗压强度=2549Mpa,完整因素KV=0.64,K1= 0.5,K2 = 0.2,K3 = 0,工程量清单计价= 319。地质构造的表面非常发达，岩体极其支离破碎,而且块强度不够强。所以它属于典型的类柔弱的岩石。2.2工程施工方法。双墙指导施工方法中的配角,以先进的小管为了减少隧道施工对

6、高速公路经营管理的影响，确保隧道建设的安全双边墙施工方法以先进的小管作为支撑角色引导。先进小管的外半径是42mm,长度是四十厘米。在施工过程中,开挖的长度是受到严格控制的，主要支撑每隔四米设置一个。30厘米厚的封闭钢筋混凝土环被襄铸在第二内衬和主要支撑之间。螺栓的形式是空心注浆和quincunx布局、直径和长度是作为轨道后,4.5米、垂直和周向所在分别是200厘米和80厘米第二内衬和主要支撑被浇铸成28厘米厚C20模型和60厘米厚C25厚钢筋混凝土模型3数值模型隧道长度是选为仿真模型,该模型被选为20米长，该模型有21850个小构件其中螺栓有3850构件(图1)。隧道围岩被认为是弹塑性材料。因

7、为支撑结构的力学性能优于围岩,所以它可以被看作是弹性材料。钢拱的影响在架子上和先进的小管喷射混凝土可以模拟使用等效的方法。Tab.1是基本力学参数的物质。为确保计算的准确性该模型维度可以设为:左和右都长50米垂直于地球表面下为50米。4进行结果分析4.1分析地表沉陷,地面沉降应严格控制,以确保隧道施工中高速公路运营管理的安全隧道施工。从图2,图像的地表沉陷隧道开挖完成后,它可以看出地表沉陷对称分布近似在双线隧道、展示W的形状。早期隧道拱顶端地面沉降规模最大，沉降值为5.31mm，这是由于早期隧道开挖完成以后，后期隧道建设造成的扰动，这和现场监测的信息和数据规则是一致的。后期隧道拱顶端地面沉降量

8、是5.31mm。在隧道中轴线附近的地表沉降小于两个隧道拱顶所在的地表沉降，沉降值只有2.87mm。可以从图二中得出的结论是隧道开挖的影响对地表沉陷趋于稳定的距离范围是中轴线直径的3.5倍,也揭示了该仿真模型的选择范围是没有错误的4.2巷道变形分析如图3所示,后期隧道拱顶端的垂直地表沉降是7.20mm,最大的垂直地表沉降值出现在早期隧道拱顶端。因为之后的隧道施工效,是7.33mm。与一般的大垮较浅深度的隧道地表沉降的现场测量值相比，顶部处理的沉降值略小。可以假定,先进的小管在加固岩石上发挥了很大作用，逆变值相对较大，早期的隧道和后期的隧道分别是9.87mm 9.85mm。分析结果表明,隧道围岩的

9、垂直缺陷值满足施工的需要、初始参数设定隧道结构是合理的。4.3支撑承载力的分析如图4所示,出现在拱脚的最大受力值是7.31Mpa.。在施工过程中应该加强现场监测的力度。从图五中以发现在拱顶和拱脚位置的螺栓的轴向力更大。最大值是42.56kN，满足抗拉强度要求。螺栓轴向力最主要的分布形式是“凸肚”式。符合螺栓轴向力在柔弱岩石上的分布格局。处在拱脚位置的少量螺栓时处于压缩状态的。可能由于主要支撑的刚度太大，结果是减少了拱脚的变形和反演胀的现象。从图六中可以看出第二内衬的应力规律和主要支撑是相似的，边墙的压力要大于其他部位最大应力值是0.2Mpa满足在中国要求的标准4.4塑性区分析从图7,便会发现,

10、塑性区主要分布在拱顶、拱门、拱门脚的位置，这也许是由于由双边墙施工方法造成的过多的应力进入了侧墙 。先进的小管的支持、初期支护,其次内衬可以预防塑性区进一步扩张,塑性区深度,不会超过一半的隧道宽度,而在允许范围内。所以隧道围岩塑性区的发隧洞的稳定性隧道仍然情况稳定。5结论隧道地表沉陷的分布在中心轴线基础上,显示W型,由于解决方案主要集中在3.5倍中心轴线的直径范围内，先进小管的支持能够加固围岩有效防止两个隧道之间塑性区的扩张。从围岩结构的变形结果可以看到后期隧道开挖地表沉陷与隧道变形对早期的隧道的影响大于早期隧道开挖对后期隧道的影响。对上述结果进行分析地面沉降、隧道周边的垂直位移，支撑的承载力

11、和塑性区双边墙建设方案是合理的。参考文献【中国岩石力学与工程】（3，623-629）三维弹塑性数值模拟软围岩位移建设的进程。佘健，何川（2006年）。【岩土力学】（4，20-33。）力学模拟及软弱岩石中的行为分析，兴建一条隧道开放。孙军，朱合华（1994年）。【岩土力学】（4，327-336）数值分析大型复杂的非线性变形机制及隧道衬砌。郑华，孙军（1997年）。【岩石和土壤力学】（3，193-200）模拟三维隧道挖掘。靳凤年、钱七虎（1996年）。【隧道与地下空间技术】（22，47-56）评价隧道的二维平面应变有限元分析的影响及三维方法核算。M.Karakus（2007年）。【中国民建工程】（

12、5，87-91）三维有限元的软土蠕变对隧道的影响。安官峰(2001年）。【中国岩土工程学报】（4，421-425)三维数值模型的地下洞室施工过程。肖明（2000年）。【施工力学】（北京科学出版社）周边复杂条件下围岩稳定性和岩石动态。朱炜沉，何满潮（1996年）【岩土力学】（5，590-594）实验研究机械特性和小间距隧道。刘颜青，韩世航，卢汝绥，马荣田（2000年）。【高速公路】（7，55-58）讨论环境对小间距研究长隧道的影响。万明富（2000年）。【隧道安全工程杂志】（2，63-68）开挖小距离隧道的方法分析。金晓广，刘炜，秦峰，汪剑华（2004年）。【中国岩石工程力学】（3，572-57

13、7）对软岩施工特性和动态行为的研究。严琦祥，何川，姚勇（2006年）。【高速公路】（12，217）大跨公路隧道结构设计与分析。刘红州，陈三佳（2006年） 图1 有限元分析模型 图2 地表沉陷图表 图3 围岩的垂直位移（mm）图4 主要支撑的等量压力 图5 螺栓的轴力图图6 次连接的等量应力 图7 围岩的塑性区 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 www.ccsenet.org/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. ConclusionsThe 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 surroun