土木工程外文翻译2

1、隧道与地下空间技术釜山巨济的交通系统：沉管隧道开创新局面Wim Janssen1, Peter de Haas 1, Young-Hoon Yoon 荷兰隧道工程顾问:大宇工程建设公司釜ft巨济交通线隧道工程技术顾问 韩国大宇工程建设公司摘 要釜ft巨济交通系统将会为釜ft和巨济两岛上的大城市提供一条道路连接。该沉管隧3.2 35 线型要求较高。基于以上诸多特点，隧道的设计和建造面临着巨大的挑战。可以预见的是这项工程将会开创沉管隧道施工技术的新局面。本文突出论述了这些特点以及阐述在土木和结构方面的问题。工程简介釜ft是韩国的第二大城市和一座重要的海港。它位于韩国的东南部，其南面和东面朝向朝鲜海

2、峡同时在釜ft北部ft势较为陡峭。该市发展迅速，近年来的人口增长超过 370 万（460 万人4850 人3/4。釜ft市的进一步发展由于其所处的地理位置而受到限制。釜ft巨济交通系统在釜ft和巨济岛之间创造了一条直接的联系线，以从客观上满足釜ft的城市扩展，在巨济岛上发展工业区，以及为釜ft市民在较短的行车距离内增加休闲娱乐的去处。巨济岛西侧目前已经与朝鲜半岛相连，在本项连接工程完工之后，从釜ft2 45 釜ftGaduk 岛之间提供一条连接，使其成为连接釜ft新港地8.204 公里长，穿越海峡并将Daejuk,JungjukJeo3240m475，230m1规划组织40 年。特许权基于该系

3、统设计理念的一个环节。GK 交通系统7 TEC/Halcrow 等合资公司作为技术顾问，从工程开始便参与该项工程。Halcrow TEC 两个合资公司分别负责关于桥梁和隧道建设方面的技术问题。永久设施的设计工作已接近完成，后续的建设的准备工作也已经开始。图1.工程地理位置图 2. 空中鸟瞰效果图2设计要求和基本闲置因素GadukDaejuk, Jungjuk and Joe 小岛连接在一起，基本GadukDaejuk1800m18mJungjuJeoJo435m404m52m36m16mDaejukGaduk25 30不延长梯度线和坡长。因此，将穿越该水域的沉管隧道设置在略低于海床平面成为一个

4、合理的选择。图 3. 线路纵剖面图岩土条件地层在隧道线路方向上呈现出不同但是在纵向自上而下依次为典型的海洋粘土、海砂、砾卵石和海床基岩。在沉管隧道沿线的海床主要以海洋粘土为主，除了在海岸线附近露出地表的海床、浅20m穿越该地层。56%85% ，均值68%14.6kN/m3。海洋情况施工位置在太平洋上，处于朝鲜海峡上并位于日本海的南面。这将影响工地现场的海洋情况。100009.2m3应的海浪周期为 15s。这种由台风引起的海浪是向南运动的。图 4.工程地质剖面图图 5. 波浪特征1.6m流向与隧道走向一致。工程所处位置的海浪包括三个主要部分：当地海风引起的波浪，主要是冬季来自东北和西北方的风；4

5、雨水带来的风，主要是夏季来自南方和东南方的风；深水海流产生的波浪，主要是夏季来自南方和东南方的风。0.5m6 次/s 大多数时间里浪高都大于此值。地震条件ft巨济交通系统的抗震等级被划分为重要的一级。Pohang 湾和釜ftYangsan 断层Yangsan 断层引起的，震源位于510km 5.76 级。这项工程采纳了两种抗震设计方案，即运营地震抗震设计（ODE）和最大地震抗震设计（MD。在抗震能力上，MDE 震荷载（保持工程结构主体的完整和安全，MDE 被采用为运营地震抗震设计，以满足所有连接处的水密性良好和钢筋的应力不超过其屈服强度的要求。本隧道的特点作为釜ft巨济交通系统一部分的沉管隧道

6、有很多特别的地方，同时也面临了很多挑战。线形的要求对海床上隧道两端的出入口产生制约；本隧道是继连接丹麦和瑞典的厄勒联络线隧道之后的世界上最长的沉管隧道；隧道基坑位于水面以下大约 50m 深处；施工地点海况恶劣；地基土异常软弱。此外，本隧道的施工方法尚未在韩国有过实际应用的经验。5隧道线形95mGaduk 5%4%的最大设计坡度。隧道西350m 处有一片8m。海洋粘土厚度最薄处所在位置，可通过人工的改良，使之满足埋藏隧道的受力要求。初步的土壤调查表明，海洋粘土的厚度在其最薄处可以通过人工改良，使它的强度得到提高以满足埋藏隧道的受力要求。在设计过程中更详细的土壤调查显示凹陷处的海洋粘土延伸范围更大

7、。由于对隧道更深位置竖向线形的修正，我们采取了更广泛的研究以克服6%的坡度未能获得通过。从砂桩，土体置换，堆载预压和深层16m 的基础和防止由于船只搁浅和海洋侵蚀的对基础造成的损害。隧道长度18 180m 9.75mDaejuk 26.5m 28.5m，以为爬坡车道提供空间。为了节省单元管段的造价，原用于厄勒海峡隧道的沉管单元的制作方法被考虑在其中。计划采用的通过移动已浇注管段来制作沉管的方法被认为可操作性和经济性不好。所以后来将制作流程变为由可移动的造管机沿管身全截面制作管段，这样就可以同时进行不同沉管单元的预制工作。许多瑞士的隧道就是使用这样的方法，有很成功的经验。图 6. 可同时制作 4

8、 个管段的预制场模型6隧道埋深防水Daejuk 35m 55m15m 深的平缓的海域内。最深的一座隧道是位于鹿特丹的格兰特隧道，结构26m60m，这样的水深有相应的规定26m 的沉管隧道上欠缺经验，但是从技术上来讲这仍然是可行的。按照设计，沉管的横截面应该有一部分处于压应力作用之下，以抵御海水的侵入。全截面要保证一次浇注成型，以避免产生横向施工缝。接头处设置双层防水条。首先需要处理的主要问题是在大位移下可有效承受水压力的防水结构。在厄勒海峡隧道中，第二层封条设置于接头处的亲水橡胶组成。而这种橡胶是不能适应地震时的移动的，所以需要一种更有力的解决方案以保证在地震时处于如此深的结构的可靠性。隧道挖

9、掘深度大多数沉管隧道的基坑都是由绞吸式挖泥船挖掘的。但是这种挖泥船的最大挖掘深得只能达到 30m。在更大的深度上就只有两种选择：抓斗式挖泥船或者拖斗式挖泥船。抓斗式挖泥船的工作效率较低并且在开阔水域施工时会产生环境污染。大型拖斗式挖泥船能够100m 的运营成本很高，所以只有在一项大的持续性工程中它们的运营经济型才能够得到体现。海洋环境安装期间沉管隧道所处的无遮蔽的海洋环境的情况很独特。气候的影响会在海上工作开展期间发挥作用。沉管操作面临的最大挑战是潮汐的作用，它会对沉管节段的拖运，受力和沉放设备产生影响。为了准确量化这些力和海浪运动，我们建立了一个数值化的波浪模型并且分析了10 2004 6

10、Jungjuk 水工和数值模型试验正与沉管节段的制作和沉放设备的安装同时进行。实验表明，尤其当0.8m6Hz 时，会产生很大的位移和荷载。结合波浪分析的结果可7以清楚地知道，在夏季下放沉管回十分困难并且需要发展特种设备。因此我们决定将此项与固定在基坑中的管段相结合的附加压载仓需要保证沉管单元的安全，并且还要考虑到沉放过程中的操作、固定和基坑回填。所以需要建立一个天气和海浪预报系统以便在沉放过程中预测浪高。对永久结构的影响DHI 实验室做了模型试验。在经历最9.2m。在直接建成后回填的土石材料渗透性很高，但是随着时间随着回填材料粒径的减小，水平和纵向力都会增大。不过这些力都是动态的，变化的方向

11、和强度都会导致隧道单元的微小移动来平衡隧道周围的水压力。隧道顶部超出原海床面的 地方大浪将会对其保护层的稳定性造成影响。水工模型试验表明，需要预制超过30 吨重的Core-loc材料应用于隧道最易受影响的部分（Gaduk 到一侧的最初的三个节段。在隧道的两头，既有岛屿都被人工接长以在岛屿和隧道之间建设过渡区。为了保护这Kordi 50，60 70 吨的四角对称圆锥钢筋混凝土管。地基土情况和隧道基础在隧道线路上，海洋粘土占据了主导地位。海洋粘土的厚度虽然各处不同但是通常都超过 30m 且正好位于隧道基础的下方。非常软弱的海洋粘土和高塑性结合其低饱和重度， 低固结度和土体的结构性质决定了基础施工方

12、法的最终选择。通常情况下，沉管隧道、回填土和保护层土石材料的重量会比开挖基坑时的掘出物重量小。由这一要求和原有土壤无沉降的假设，如果隧道的质量小于原有土层的质量，理论上可以确定建筑结构不会发生沉降。在此基础之上，普通沉管隧道通常不需要修建桩基础。只有少部分隧道基于设计者的理论需要桩基础。比如荷兰阿姆斯特丹的 IJ 隧道、鹿特丹的地铁、阿姆斯特丹 Zeebger 隧道的一部分和中国宁波的长虹隧道，基于各种而原因采用了桩基础。隧道在釜ft一侧的情况比较特别。回填土的单位重量要求比原覆土重量大，以使隧道8保持稳定。这样做的结果是增加了回填土的有效应力和回填土与隧道的沉降。增加的有效应力可能超过预期估

13、计，这意味着因硬土的减少导致的沉降增加风险（二次压缩指数与压14巨大沉降。这是因为隧道较深且海洋条件严峻而导致的挖掘精度过低。图 7. 隧道划分模型和开挖单元部分混凝土隧道能够适应这种不均匀沉降。但是应当避免在接头处的沉降。鉴于此， 我们决定用深层搅拌桩来改良海洋粘土。用这种方法，直接将水泥注入粘土中，就形成了1.8m1.8m 将这种不良影响纳入既有的经验范围之内。使用这种混合搅拌桩也会减少因隧道线路所经过的从海洋粘土到裸露基岩的刚度变化的影响。从而减少这些部分的不同沉降。图 8. 制作 70 米深混合桩的沿岸设备9结论釜ft巨济交通系统的隧道具有如此多的特点是有很多原因的。上文介绍了本工程并

14、突出了这些特点。它们已经远远超出了现在混凝土沉管隧道施工技术的水平。并非所有的特殊设计在工程开始之前就已经被全面地考虑到，而是随着工程的进行同步设计的。在写就本文的时候尚有很多问题未全部解决，但是最根本的设计已经完成。我们期待此条交通连接线的完工能够开创沉管隧道施工技术在深水、严峻的海洋和地质条件下应用的新局面。10Tunnelling and Underground Space TechnologyVolume 21, Issues 3-4, May-July 2006, Page 332Busan Link: Immersed Tunnel Opening NewHorizonsWim J

15、anssen1, Peter de Haas 1, Young-Hoon Yoon2Tunnel Engineering Consultants, the Netherlands: Technical Advisor to Daewoo E&C for Busan - Geoje Fixed LinkDaewoo E&C, KoreaABSTRACTThe Busan Geoje Fixed Link will provide a road connection between the metropolis of Busan and Geoje Island. The Link compris

16、es amongst others two cable stayed bridges and an under water tunnel constructed as a concrete immersed tube tunnel.The immersed tunnel has a number of special features: its length of 3,2 km, the water depth of over 35 m, the severe marine conditions, the soft subsoil and alignment constraints. Comb

17、ined with the scale of the project these features make the design and the construction of the tunnel a major challenge. It is expected that the project will open up new horizons for the use of immersed tunnel technology. This paper highlights these special features and concentrates on the civil and

18、structural aspects only.INTRODUCTIONBusan is the second largest city and a major harbour in South Korea. It is located in the southeast and bordered by the Korean Strait at the south and east side whilst at the north steep mountains arise. The city is developing rapidly; the population grew over the

19、 recent years to 3,7 million inhabitants in the city (4,6 million in the agglomeration). The density of population is 4850 inhabitants/km2 which is about three-quarter of the density of Hong Kong. The options for expansion are limited due to its geographic location. The Busan Geoje Link has to creat

20、e a direct link between Geoje Island and the city of Busan with the objective to allow Busan to expand, to develop industrial areas on Geoje and to add recreational facilities within driving distance of Busan city. Geoje Island is currently connected to the mainland at the west side of the island. T

21、he two hours drive by car from Busan city to Geoje will be reduced to 45 minutes after completion of the Link. The Busan Geoje Fixed Link will provide a road connection between Geoje Island and Gaduk Island as part of a dual carriage motorway connecting the Busan Newport region to the island of Geoj

22、e. The Link will be 8.204 km in total, crosses navigation channels and links the small island of Daejuk, Jungjuk and Jeo, which are uninhabited. principle components of the link are an immerse tunnel 3240 m long with two-lane traffic tubes in each direction and two cable stayed bridges with respecti

23、vely one main span of 475 m and a two main spans of 230 m each.11THE PROJECTOrganizationThe project is developed as a Public Private Partnership where GK Fixed Link Corporation has been awarded the concession to design, construct and operate the Link for a period of 40 years. The concession is based

24、 ona conceptualdesign for theLink. The GK Fixed Link Corporation consists of seven Korean contractors amongst them Daewoo Engineering & Construction Co. Ltd. as the leadingcompany of the concessionaire. The joint venture TEC/Halcrow is appointed as Technical Advisor and as such involved from the sta

25、rt of the project. In the joint venture Halcrow and TEC take care of the bridge and tunnel related aspects respectively.The design of the permanent works is almost completed and construction in advance of the permanentworks has started.Figure 1. eographic location of siteFigure 2. Aerial overview of

26、 the project.12Design requirements and basic constraintsThe project has to provide a fixed link from Gaduk island via Daejuk, Jungjuk and Joe island to Geoje island. The basic layout is defined by the requirements to the three navigation channels. A main channel between Gaduk and Daejuk island with

27、a width of 1800 m and a depth of 18 m. For this navigation channel no height restriction is accepted by the Authorities and as such a tunnel has been the obvious way to cross. For the two secondary channels located between Jungjuk-Jeo island and Joe-Geoje island, a minimum width of 435 m and two tim

28、es 202 m, clearance heights of 52 and 36 m respectively are required. Water depth for both secondary channels is 16 m.The relative steep shores of Daejuk island and Gaduk island and the deep position of a bored tunnel of about 25 to 30 m below the seabed make it physically impossible to fit an align

29、ment for a bored tunnel in between these two islands. The gradient of the alignment would be too great and slopes too long for driving comfort and safety. For this reason the crossing by an immersed tunnel with its position just under the seabed has been a logical choice.Figure 3. Longitudinal secti

30、on of the linkGeotechnicalThe geological strata vary along the tunnel alignment but top down typical consist of marine clay followed by marine sand and gravel on top of the bedrock.Marine clay is forming the seabed along the immersed tunnel alignment except in the near shore areas where outcrops of

31、bedrock and shallow sand and gravel layers are found. The thickness of the marine clay exceeds 20 m along most of the immersed tunnel alignment. Most of immersed tunnel will consequently be founded in this layer.The marine clay comprises normally consolidated to slightly over-consolidated soft struc

32、tured clays. These clays have been deposited during the Holocene epoch. The major part of the marine clay, from seabed down, is very soft to soft and of very high plasticity to extremely high plasticity. The marine clay plasticity index ranges from 56% to 85% with an average of 68%.The range of satu

33、rated unit weights of marine clay is 13.9 to 15.4kN/m3, with a mean value of 14.6k N/ m3.Marine conditionsThe site is exposed to the Pacific Ocean via the Korean Strait and the Sea Of Japan at the South. This affects the marine conditions on site. An impression is given below by the 10000 years retu

34、rn period hydrological conditions for the south wave direction. The maximum design wave height13Hs is 9,20 m and the corresponding mean wave period Tm is 15 sec. The principle wave direction due to typhoons is South.Figure 4. Geological profileFigure 5. Wave characteristicsThe current is mainly infl

35、uenced by the tide, which is a typically semi-diurnal type with a spring tide range of 1,60 m with a maximum current of 0.80 m/sec at the tunnel alignment.The waves on site comprise three main components:Locally generated wind waves, mainly from the northwest and northeast during thewinter14season;D

36、eep water generated wind waves, mainly from the South and South east, during the season;Deep water swell waves, mainly from the South and South east.During construction of the marine works the swell waves with a Hs of more than 0.50 m and a periodof 6 seconds have to be takeninto account.In the summ

37、er season most of the waves exceedsthese values.Seismic conditionsAccording to the Korean Research on Earthquake Design Standard the Busan Link is classified as an aseismatic grade I structure with regard to theimportance level.The seisemicity of South Korea is mainly governed by the tsushima offsho

38、re and the yangsan onshore fault systems located in the depression between the Pohang Bay and Busan. However, only few major events have been recorded on those faults. This explain why, on a large scale basis, seismic hazard analyses leads to low hazards for Korea. The closest fault to the project s

39、ite is the Yangsan onshore fault and the decisive (characteristic) earthquake will be an event on the Yangsan Fault at a distance of 5-10 kmto the east of the project site and with a moment magnitude of 5.7-6. A two-level earthquake hazard design approach has been adopted quake hazard levels are the

40、 operating design earthquake (ODE) and the maximum design earthquake (MDE). In respect of strength the MDE is regarded as Ultimate Limit State, but in order to survive seismic loads (prevention of major failure and maintaining safety) the MDE is regarded as service limit state, with the requirements

41、 that all joints shall remain watertight and rebar stress does not exceed yield strength fyk.The tunnels special featuresIn a number of ways the immersed tunnel part of the Busan-Geoje Link is special and imposes a number of challenges.The alignment constraints impose a position above seabed at both

42、 outer ends of the alignment;It is after the .resund Link between Denmark and Sweden the longest immersed concrete in the world;-The tunnel trench reaches to a depth of about 50m below mean water level;The site is exposed to severe marine conditions;The subsoil is characterised by its extreme weakne

43、ss.And in addition to this the construction method by an unknown phenomenon in South Korea.Tunnel alignmentFrom the deepest point the alignment climbs over 95m to the highest elevation of the cable stayed bridge over the main navigation channel. Maximum gradient is 4,73%, a little less compared to t

44、he gradient towards the east portal at Gaduk island which is 5%. Both exceed the maximum design gradient under standard conditions of 4%. The gradient at the west side of the tunnel15alignment conflicts with the design objective to place the tunnel under the seabed. Due to a local depression in the

45、seabed at about 350 meters east of the western portal the underside of the tunnel structure is positioned about 8 m above the original seabed.The preliminary soil investigations indicated the tunnel. More detailed soil investigations during design showed an extension of the marine clay under the dep

46、ressed seabed. More detailed soil investigations during design showed an extension of the marine clay under the depressed seabed.As a modification of the vertical alignment to a deeper position, resulting in a gradient of 6% was not an option for the Authorities an extensive study has been carried o

47、ut in order to explore the technical options to overcome the problem. From a number of alternatives varying from sand compaction piles, soil replacement, preloading and deep cement mixing the latter has been selected as technical most appropriate and economical acceptable method. The areas with DCM

48、piles will be extended over a considerable distance at both sides of the tunnel in order to support the sub-sea embankment which raises about 16 m above the original seabed and has to protect the tunnel against stranding ships and erosion.TunnellengthThe current design comprises 18element of about 1

49、80m in length.Theconcrete cross section is 60m2 and the tunnel width is 26.5m and the height 9.75m.The two elements at the daejuk island side are tapered and vary in width from 26.50 m to 28.50 m to create space for a climbing lane. In order to economize the production of the elements the principle

50、used for the element production of the ?resund has been considered. The casting at a fixed location moving the elements by skidding was considered toocomplex, costly and as such noteconomical justified. The casting facility has been changed into a system using a moveable casting facility along the e

51、lement length allowing full section casting at various locations. The choice for this construction method has been supported by the good experience with this method on a number of tunnel projects in Switzerland.16Figure 6. Model of precast yard for fabrication of 4 tunnel elementsTunnel depthWaterpr

52、oofingAt the daejuk island side of the alignment the seabed is about 35m below mean water level,resultingin 47,5 m water to the underside of structure,increasing till about 55m due to wave action.All concrete segmental tunnels constructed in Western Europe are in moderate water depth of about 15 m.

53、The deepest one is the Calandtunnel in Rotterdam with 26 m water to the underside of structure. The Bosphorus immersed tube recently under construction will have locally almost 60 m. The deepalignment has an impact on the immersion and provisions to prevent water ingress in the tunnel. In spite of t

54、he fact that the experience with concrete immersed tunnels is limited to a water depth of maximum 26 m the concept of a segmented concrete tunnel has found technical feasible. The cross section has been designed such that at least a defined part of the cross section is under compressive stress assur

55、ing a sufficient barrier against ingress water through the concrete. The full cross section will be casted in one process avoiding horizontal construction joints. The segmental joints will be provided with a double seal. The primary deal is a modified injectable waterstop which can accomodate the wa

56、ter pressure under great displacements. In the .resund Link tunnel the second seal consisted of a hydrophilic rubber placed in the joint. The expected displacements during an earthquake cannot be accommodated by this rubber and a more robust solution building in omegas () in every segment joint are

57、considered in order to assure sufficient reliability during an earthquake under the great water depth.Dredging in relation to tunnel depthMost of the trenches for immersed tunnels are dredged with cutter suction dredger.This type of dredger can dredge only up to 30 meter water depth. For the deeper

58、sections there are only two alternatives; grab dredgers and trailer hopper dredgers. Grab dredgers can achieve relatively low production rates only and could cause environmental problems when working with open buckets. Large hopper trailer dredgers can excavate up to 100-meter water depth and are us

59、ed in Korea for mining sand for reclamation works. Due to the high operational cost these large dredgers can only operate economical if they can work continuously during a larger period of time.Marine conditionsDuring installationThe exposed conditions of the sea are unique for the location of an im

60、mersed tunnel.This have an impact on the weather window during which marine work can take place.The mayor challenge for the immersion operation is the swell waves, which impose large movements and forces on the tunnel element and the immersion equipment.In order to quantify these forces and movement