交通隧道在高烈度地震區(qū)洞口動(dòng)態(tài)行為的探究畢業(yè)設(shè)計(jì)外文翻譯

1、DYNAMIC BEHAVIOR OF PORTAL PART OF TRAFFIC TUNNEL IN HIGH-INTENSITY EARTHQUAKE AREASHEN Yusheng1,2 ,GAO Bo2 ,WANG Zhengzheng2 ,WANG Yingxue21Postdoctoral Station of Mechanics, Southwest Jiaotong University, Chengdu 610031, China; email:sys1997. 2School of Civil Engineering,Southwest Jiaotong Univers

2、ity, Chengdu 610031, China; Abstract: A large-scale shaking table test is accomplished on the dynamic response and failure modes of the tunnel. The result is that the largest dynamic response of tunnel structure appears at the side-wall and the shear or fracturing damage appears at the invert, which

3、 is basically the same damage state with tunnel engineering in 5.12 Wen Chuan earthquake. The internal force value of tunnel structure minish and the numbers of cracks reduce after the shock absorption layer is set up in model test, and optimize the stress state of tunnel. The surface cracks of tunn

4、el model appear firstly at both spandrels and develop diagonally at the tunnel entrance. The cracks arise "X"-shape distribution on the surface of the model soil. There are a lot of circumferential cracks at tunnel portal under the condition of dynamic loads, and most of longitudinal crack

5、s or oblique cracks can terminate when extending to the circumferential cracks. So that it is proposed that there should be designed more shock absorption seams in the vicinity of tunnel portal in order to be propitious to damping the earthquake energy. Key words: dynamic behavior, shaking table tes

6、t, high-intensity earthquake area1 Introduction It is regrettable that the people's lives and property have suffered great losses during "5 12" Wenchuan earthquake in Sichuan province. At the same time the civil transport engineering are damaged to some extent, including the tunnel eng

7、ineering. Tunnel damage survey shows that the tunnel portal section is the most easily to destroy and is the most weak parts(Li,2006). Especially at the high-intensity earthquake area, the stability analysis of the tunnel entrance, portal and side slope will be focused on in the field of the anti-se

8、ismic technology research. The mechanical characteristic of tunnel lining is a considerably complex process, the grade of surrounding rock is various and there are a variety of non-linear features(Luo,2008). It is a effective way to research the tunnel anti-seismic characteristic by the shaking tabl

9、e test in the earthquake engineering field because the establishment of non-linear equations of motion and the numerical solution is still not perfect(Chen,2006; Gong,2002; Yang, 2003; Zhou, 2005). It is inevitable to encounter any problems that the tunnel projects could be possible to adopted in th

10、e vicinity of the fault or high-intensity earthquake area during the construction of the traffic engineering in Western China regions (in particular the South-West). The line from Yaan to Lugu highway is across the seismic faults several times (Xianshui River fault zone and Anning River fault zone)

11、and the seismic fortification intensity is from degrees to degrees, in particularly degrees at local regions. The peak acceleration of ground motion is from 0.15g 0.4g, which parameters are the relative large in the current construction of the highway. In this paper, the dynamic characteristics of t

12、unnel structure is analyzed at the mountain tunnel portal according to the actual engineering, thus the law of stress-strain and failure mode of the tunnel and surrounding rock are researched under the ground motion load, which provides an important reference for the design and construction of the h

13、ighway tunnel in high-intensity earthquake area.2 Relying on engineering conditions and shaking table test device 2.1 Geological conditions Model test was accomplished in august 2007, based on certain tunnel project where there is through the region of seismic fortification intensity degrees and may

14、 be active faults in Ya-Lu highway. Based on drilling and surface survey, the tunnel stratum is mostly triassic systemJurassic system, silty mudstone, pelitic siltstone, quartz sandstone, carbargillite, Cenozoic overlying Holocene Quaternary cover. 2.2 Shaking table test The shaking table at the Tra

15、ction Power State Key Laboratory is the main facility for experimental research into earthquake engineering at Southwest Jiaotong University. The model test adopts the bi-directional seismic shake table, which table size is 2.5 m by 2.5 m, the platform capable of carrying a maximum payload of 30t an

16、d the vibration mode is for X, Y two direction and four freedom degrees. The frequency range is 0.1 30 Hz, and the peak acceleration of X or Y direction is 1.0g respectively. It is driven horizontally and vertically by four 20kN servo actuators giving full control of motion of the platform in 4 DOF

17、simultaneously. 3 Design of model test similar parameters Taking into account the model border effect, the width of the box model should be more than 6 times the tunnel width, thus the similar parameters are determined(geometry similar CL =30, Youngs modulus CE = 45, density C =1.5) and Shen (2008)

18、described the rest of physical similar parameters. 3.1 Design of similar material for surrounding rock and secondary lining According to the similar relation and the physico-mechanical parameters of surrounding rock in situ, the similar material selected is consisted of flyash, river sand and oil af

19、ter the orthogonal tests are repeated dozens of times. At last these similar material will be mixed according to a certain similar ratio.The secondary lining material selected is consisted of plaster, quartz sand, barite, water by a certain percentage of preparation, which mechanical parameters are

20、shown in Table. 1. Table.1 Mechanical parameters of concrete similar materialparametersDesign valueTheory valueTest valueSimilitude relation (kN/m3)2516.717.0reasonableE(MPa)29.50.660.72reasonablec (MPa)12.50.30.426approximately4 Test measurement and scheme 4.1 Strain measurement of tunnel structure

21、Strain gauges are firstly arranged for the tunnel site where the internal force and deformation of tunnel is maximal. The sensor wire should be firmly fixed at the surface of the model structure and fetched out from the certain position where the model displacement is lesser at that direction. The s

22、chematic diagram of measurement points are laid in Figure.1 in order to verify the dynamic response law of tunnel structure. Figure.1 Layout scheme of sensors Figure.2 Accelerations time-histories curve4.2 Test load -earthquake wave The earthquake waves adopted is the artificial wave that is synthes

23、ized by the Sichuan Seismological Bureau under the conditions of the site response spectrum synthesis in model test. The exceedance probability of earthquake waves is2% , the original peak acceleration is 0.67g, the hold time is about 20s in the part of strong shock, most of the earthquake waves Ene

24、rgy is less than 15s and is within 15Hz in the frequency (in Figure. 2). 4.3 Test scheme In Table.2, the case 2 and 3 are to study the effect of the shock absorption layer. The polyethylene material that is adopted to the shock absorption layer circumfuses the outside surface of the tunnel lining (t

25、he invert is not laid). Table.2 Test conditions of mountain tunnel modelnumbercaseremark1single-tunnel portalvalidating the anti-seismic characteristic of single-tunnel 2bi-tunnel portalbi-tunnel have not shock absorption measure3bi-tunnel portalsingle-tunnel has shock absorption measure5 Model test

26、 results and analysis 5.1 Strain response analysis of tunnel structure There are more than 30 strain gauges at the key positions, thus the strain response law of the tunnel lining is obtained by the strain gauges. In Figure.3, when the acceleration 0.4g(equivalent to degrees) is input from shaking t

27、able, the maximum strain amplitude value of the vault is 22 in the case 2, while the case 3 is for 6.5, thus the strain amplitude value is obviously decreased after the shock absorption measure is taken. The maximum strain amplitude value of the invert do not change because the shock absorption laye

28、r is not set at the right tunnel invert. So it is obvious for the damping effect that the shock absorption measures are taken for tunnel structure at the tunnel portal. a) Strain curve of vault in case 2. b) Strain curve of invert in case 2. c) Strain curve of vault in case 3. d) Strain curve of inv

29、ert in case 3.Figure.3 Time-histories of strain at different points of right-tunnel( a=0.4g)The structural strain values recorded from various measuring points do not tend to be zero after the vibration is over, which phenomenon is mainly due to the rock and soil producing permanent deformation arou

30、nd the tunnel structure under the condition of the dynamic loading, so that the additional seismic strains occur on tunnel structure5.2 Patterns of damage of model test comparative analysis There are various cracks on the surface of the similitude material in both cases, but those cracks of tunnel m

31、odel appear firstly on both spandrels and then develop diagonally. In Figure. 4a, the cracks arise "X"-shape distribution on the surface of the model soil and the model soil cracks of right tunnel are more than left tunnel at the surface of tunnel. There is a 45 °angle between the dir

32、ection of cracks and the tunnel longitudinal direction, the numbers of cracks in right tunnel close to the side of border are less than the other side and there appear a lot of run-through cracks on the surface of the model soil due to small distance of both tunnels. a) case2 (no shock absorption la

33、yer) b) case3 (shock absorption layer)Figure.4 Failure modes on the surface of tunnel model materialIn Figure. 4b, there is less cracks on the surface of model soil after the shock orption layer is set up at right tunnel, which weakens the interaction between the model soil and tunnel structure. It

34、is obviously effect that a certain thickness shock absorption layer is designed at the mountain tunnel portal, at the same time it is proposed that the slope of tunnel portal should be reinforced in order to prevent the secondary disasters(such as landslide, slope instability, etc) due to earthquake

35、.5.3 Contrast or analysis of failure modes in tunnel structure In Figure. 5, the tunnel structure appears a number of longitudinal cracks, diagonal cracks and shear cracks at the foot of side-wall with the increasing seismic loads, because the shock absorption layer is not designed at tunnel portal

36、in case 2. But in case 3, the overall tunnel structure is not apparently damage, only are there less micro-cracks at local position of tunnel structure and the tunnel invert arises damage or destruction. When the stiffness of the tunnel portal structure is much larger than the strata stiffness, the

37、surrounding rock displacement could have made underground structure forced deformation while happening earthquake, at the same time the earthquake inertia force obviously intensify at the tunnel portal, which results in tunnel structure to appear cracks. The model soil and model structure could be e

38、asily to appear shear or tensile destruction at tunnel portal under the action of both surrounding rock displacement and earthquake inertia force. a)Case2 (without shock absorption layer) b)Case3 (shock absorption layer)Figure.5 Failure modes of tunnel modelThere are a lot of circumferential cracks

39、at tunnel portal, where the numbers of cracks are more than others position, as well as most of longitudinal cracks or diagonal cracks can terminate when extending to the circumferential cracks. So that it is proposed that there should be set up more shock absorption seams in the vicinity of tunnel

40、portal in order to be propitious to damping the earthquake energy. Shaking table model test shows that the tunnel damage position concentrates on the tunnel portal, which damage state is the same with the tunnel engineering damage in “Sichuan 5.12 Wenchuan earthquake”. Zhe hu shan tunnel occurred se

41、veral times landslide and structure destruction during the Wenchuan earthquake and its aftershocks, which bring greater traffic obstacles for the rescue and disaster relief under the common effects secondary disasters and damage of the tunnel structure itself at tunnel portal. 6 Conclusions Here we

42、may draw the following conclusions. (1) According to the tunnel internal force changes and failure modes, the largest dynamic response of tunnel structure appears at the side-wall and the shear or fracturing damage appears at the invert, which damage state is basically the same with tunnel engineeri

43、ng damage in 5.12 Wen Chuan earthquake. So that this model test is reliable.(2) The internal force value of tunnel structure minish and the numbers of cracks reduce after the shock absorption layer is set up in model test, at the same time it can greatly reduce the earthquake destruction and optimiz

44、e the stress state of tunnel. So it is provide a certain reference for the anti-seismic design and construction of mountain tunnel in high-intensity earthquake area. (3) The surface cracks of tunnel model appear firstly on both spandrels and develop diagonally in tunnel entrance. The cracks arise &q

45、uot;X"-shape distribution on the surface of the model soil, at the same time it is proposed that the slope of tunnel portal should be reinforced in order to prevent the secondary disasters(such as landslide, slope instability, etc) due to earthquake(4) There are a lot of circumferential cracks

46、at tunnel portal under the condition of dynamic loads, and most of longitudinal cracks or oblique cracks can terminate when extending to the circumferential cracks. So that it is proposed that there should be set up more shock absorption seams in the vicinity of tunnel portal in order to be propitio

47、us to damping the earthquake energy.Acknowledgements This study is funded by the Postdoctoral foundation of China (No.20080431267), the National Natural Science Foundation of China(No.50878187) and the Foundation of Southwest Jiaotong University(No. 2007B19)References Chen, G. X. (2006). A large-sca

48、le shaking table test for dynamic soil-metro tunnel interaction test scheme. Earthquake engineering and engineering vibration, 26(6):178 183. Gong, B. N. (2002). Experimental Research on Dynamic Interaction of Underground Structure and SoilJ. Journal of China Three Gorges Univ, (6):493496. Li, Y. S.

49、 (2006). Study on earthquake responses and vibration-absorption measures for mountain tunnel. Shanghai: Tongji University. Luo, D. L. (2008). Researchon Simulating Material of Surrounding Rock in Tunnel Seismic Model Experiment, Journalof Shijiazhuang Railway Institute (Natural Science), 21(3),7073.

50、 Shen,Y. S. (2008). Model test for a road tunnel in the region of high seismic intensity. Modern Tunneling Technology,05:38-43. Yang, L.D. (2003). Shaking table test on metro station structures in soft. Modern Tunnelling Technology, (1):711. Zhou, L.C. (2005). Shaking Table Tests for the Seismic Sim

51、ulation of Underground Structure, Underground Space and Engineering,1(2):182187. 交通隧道在高烈度地震區(qū)洞口動(dòng)態(tài)行為的探究申宇生1,2，高博2，王錚錚2，王映雪21力學(xué)博士后流動(dòng)站, 西南交通大學(xué)，成都610031, 中國,郵箱：sys1997。2土木工程學(xué)院，西南交通大學(xué)，成都610031，中國。摘要：通過大型振動(dòng)臺(tái)試驗(yàn)完成隧道的動(dòng)力響應(yīng)和失效模式的探究。其結(jié)果是，最大動(dòng)態(tài)響應(yīng)出現(xiàn)在隧道結(jié)構(gòu)側(cè)壁和剪切或壓裂損害位置，比如對(duì)國家與隧道工程造成重大損害的“5.12”汶川大地震。隧道結(jié)構(gòu)內(nèi)力值減小的數(shù)量和裂縫減少后減震

52、層的關(guān)系是建立在模型試驗(yàn)的基礎(chǔ)上，且可以優(yōu)化到應(yīng)力狀態(tài)的。表面裂紋和斜裂縫首先在隧隧道入口處出現(xiàn)。裂縫出現(xiàn)“×”形分布模型，有大量的環(huán)向裂紋在隧道入口條件下的動(dòng)態(tài)負(fù)載，和大多數(shù)縱向裂縫或斜裂縫可以終止時(shí)，延伸到環(huán)向裂紋。因此，建議設(shè)計(jì)應(yīng)更加注重隧道入口附近的減震縫設(shè)計(jì)，這有利于阻尼地震能量。關(guān)鍵詞：動(dòng)態(tài)特性，振動(dòng)臺(tái)試驗(yàn)，高烈度地震區(qū)1簡(jiǎn)介遺憾的是，發(fā)生在四川省的“5.12”汶川大地震讓人民生命財(cái)產(chǎn)遭受巨大損失。同時(shí)，民用運(yùn)輸工程有一定程度的破壞，包括隧道工程。隧道病害調(diào)查表明，隧道洞口段是最容易破壞和是最薄弱部位。特別是在高烈度地震區(qū)，用于穩(wěn)定性分析的隧道入口，入口側(cè)坡的重點(diǎn)將是在該

53、領(lǐng)域的抗震技術(shù)研究。機(jī)械特性襯砌是一個(gè)相當(dāng)復(fù)雜的過程，隧道隨著圍巖分級(jí)的不同，有多種非線性特征。振動(dòng)臺(tái)試驗(yàn)研究隧道抗震性能是一個(gè)有效的方法。但是，在地震工程領(lǐng)域建立了非線性運(yùn)動(dòng)方程和數(shù)值的解決辦法仍然是不完美的。隧道隨時(shí)都可能遇到任何問題，這是不可避免的。隧道工程尤其是高烈度地震區(qū)的隧道在施工期間有可能遇到不可預(yù)知的交通工程故障，比如在中國西部地區(qū)（尤其是西南）。本線是從雅安到瀘沽的高速公路，穿越地震斷裂多次（鮮水河斷裂帶和安寧河斷裂帶）和抗震設(shè)防烈度的度度，特別是在局部地區(qū)度。地面運(yùn)動(dòng)峰值加速度是從0.4g 0.15 g，該參數(shù)是相對(duì)大的公路建設(shè)來選定。在本文中，通過探究動(dòng)態(tài)隧道結(jié)構(gòu)的特點(diǎn)，

54、根據(jù)實(shí)際工程分析在山嶺隧道洞口。應(yīng)用應(yīng)力-應(yīng)變和破壞模式，研究隧道圍巖下的地面運(yùn)動(dòng)負(fù)荷，它提供了在高烈度地震區(qū)建設(shè)的公路隧道一個(gè)重要的設(shè)計(jì)參考。2依托工程條件和振動(dòng)臺(tái)試驗(yàn)裝置2.1地質(zhì)條件本模型試驗(yàn)是始于2007年8月，探究通過抗震設(shè)防烈度度的地區(qū)和可活動(dòng)斷層公路的隧道工程。根據(jù)鉆井和地面調(diào)查，隧道地層主要是侏羅系三疊系，粉砂質(zhì)泥巖，泥質(zhì)粉砂巖，石英砂巖，碳質(zhì)頁巖，新生代第四紀(jì)全新世蓋覆。2.2振動(dòng)臺(tái)試驗(yàn)振動(dòng)臺(tái)的牽引動(dòng)力來自于國家重點(diǎn)實(shí)驗(yàn)室的主要設(shè)施，位于地震工程西南交通大學(xué)。模型試驗(yàn)采用雙向地震振動(dòng)臺(tái)，其臺(tái)面尺寸為2.5米×2.5米的平臺(tái)，可攜帶最大有效載荷設(shè)備和振動(dòng)模式，是雙向和

55、四自由度。頻率范圍是0.130赫茲，對(duì)峰值和加速度方向分別試驗(yàn)。同時(shí)，它是由水平和垂直方向的四個(gè)20 KN伺服驅(qū)動(dòng)器充分控制運(yùn)動(dòng)平臺(tái)的4自由度的。3設(shè)計(jì)的模型試驗(yàn)相似參數(shù)考慮到模型的邊界效應(yīng)，盒子的寬度模式應(yīng)該是6倍以上的隧道的寬度，因此，類似的參數(shù)確定，并用來描述其他物理相似參數(shù)。根據(jù)相似關(guān)系和圍巖物理力學(xué)參數(shù)的原位，類似材料的選擇是由粉煤灰，河砂和油經(jīng)過正交試驗(yàn)重復(fù)數(shù)十次。最后，這些類似的材料將按照一定的比例混合。 二襯砌選定的材料是由石膏，石英砂，重晶石，水按一定比例配制，其力學(xué)參數(shù)見表1。表1混凝土相似材料的力學(xué)參數(shù)參數(shù)設(shè)計(jì)值理論價(jià)值測(cè)試值相似關(guān)系(kN/m3)2516.717.0合理的E(MPa)29.50.660.72合理的c (MPa)12.50.30.426近似的4測(cè)試測(cè)量方案4.1隧道結(jié)構(gòu)的應(yīng)變測(cè)量應(yīng)變計(jì)首先檢測(cè)隧道工地的內(nèi)力和變形，找出隧道最大的位置。傳感器應(yīng)牢固地固定在模型結(jié)構(gòu)的表面和并取出一定位置上的新型位移其大小及方向。示意圖的測(cè)量點(diǎn)，隧道結(jié)構(gòu)動(dòng)力響應(yīng)規(guī)律探究見圖1。圖1 傳感器布局方案圖 圖2 加速度時(shí)程曲線4.2荷載檢測(cè)-地震波地震波