The challenges involved in concrete works of Marmaray immersed tunnel with service life beyond 100 years

Marmaray immersed tube crossing, located at the entrance of Bosphorus Strait of Istanbul, will be one of the unique infrastructure facility bringing great engineering challenges in immersed tunnel technology. The employer requires a minimum design life of 100 years for the immersed tunnel structure that will be under exposure of the highest saline water pressure at the depth of 58 m that has never been experienced yet in the history of immersed tube systems. Since the structural concrete is to be subjected to extremely aggressive environmental conditions during expected long-term service life, the quality assurance of the immersed tunnel has been ensured by setting a series of effective technical requirements taking into account the potential durability risks and predictive models in design phase, outputs of pre-testing activities and potential difficulties at construction period. The objective of this paper is to present some major steps involved in concrete works of this megaproject by giving the highlights from laboratory scale researches to the execution of the work at construction site.     

超大截面沉管隧道预制构件温控试验

港珠澳大桥沉管隧道是我国交通建设史上技术最复杂、标准最高的海中隧道工程,也是当今世界范围内规模最大的海底沉管公路隧道.如何在混凝土沉管隧道管节制作过程中控制温度与裂缝是决定工程质量的关键技术之一.从热传导问题的基本理论出发,讨论了现有国内外混凝土温度控制指标,设计完成了沉管隧道试浇块现场试验以及相关室内试验.试验结果表...     

Considerations and strategies behind the design and construction requirements of the Istanbul Strait immersed tunnel

This being a design-build project, the challenge faced during preparations of the Employer’s requirements for design and construction of the Istanbul Strait immersed tunnel was to give the contractor as much freedom as possible and yet specify enough so that the Employer obtained the required facility. When completed, this will be a world-class facility. This paper discusses on a strategic level many of the aspects to be presented by the author in two papers in later sessions of the day. Unusual features of this crossing include the deepest ever immersed tunnel crossing, extra waterproofing requirements, strong currents with bi-directional flow, close proximity of the North Anatolian Fault which is predicted to have a major seismic event during the life of the tunnel, and the method of connecting the adjacent bored tunnels to the immersed tunnel. Safety during tunnel construction and operation has been paramount, and resulted in changes to contract packaging and extra requirements. Other challenges discussed include fish migration, control of an international waterway, environmental issues and ensuring the stability of the soft soils during a seismic event.     

超长沉管隧道纵向地震响应频域分析方法

中国目前还没有专门的沉管隧道抗震规范,且以往的地震响应分析方法考虑的因素不够全面,比如通常忽略隧道惯性的影响、不能考虑复杂地基条件、不能考虑沉管底部非一致地震激励以及不能考虑土体动刚度系数和阻尼系数的外部激励频率相关性等。基于此考虑,在借鉴日本水下隧道抗震设计规范所推荐方法(响应位移法)的基础上,利用Winkler地基梁理论和快速Fourier变换技术,建立了动力Winkler地基梁频域分析方法。最后,分别采用响应位移法和本文所提之分析方法对港珠澳大桥海底沉管隧道工程进行了纵向地震响应计算,对两种计算方法作了讨论和评价,并提出了一些对港珠澳沉管隧道工程抗震设计具有参考价值的结论和建议。     

电缆隧道长距离泵送混凝土施工工艺

上海世博北京西路～华夏西路电力电缆隧道工程中,隧道内部现浇混凝土的最大水平输送距离达800m,已超出一般混凝土泵的理论输送极限。因此施工中,对输送泵的选型、混凝土配比,以及现场泵送管路布置等方面都进行了优化,顺利实现了804m最长水平输送距离的混凝土结构浇筑任务。本文结合工程实例,阐述了中等直径盾构法隧道施工中,长距离泵送混凝土容易出现的一些问题和宜采取的对策,可为今后类似工程提供借鉴。     

超深埋海底沉管隧道接头防水设计探讨

对建设中的港珠澳大桥工程岛隧标段中的沉管隧道工程作了详细介绍,并针对超深埋海底沉管隧道的管节接头与节段接头防水设计所遇到的一系列问题进行了深入探讨,重点阐述了GINA止水带、OMEGA止水带、中埋式可注浆止水带的防水技术。     

小净距隧道设计研究与应用

1前言随着我国高等级公路建设的迅猛发展,隧道越来越多的出现在公路建设中,目前在山区高等级公路建设中遇到的1000 m以下的中、短隧道较多。在布线时往往为满足规范要求的隧道间距[1],使得道路与隧道接线时有一个三角形过渡区,尤其在碰到鸡爪地形时,常会出现隧道群方案、桥隧相     

The Limehouse Link: the architectural and cultural history of a monumental road tunnel in London's Docklands

In the Docklands area of London lies the ‘Limehouse Link’, a dual-bore road tunnel used by around 80,000 cars each day. A monumental and highly expensive piece of construction, the Limehouse Link has nonetheless received almost no attention from architectural historians or others concerned with the history of construction, engineering or urban development.

This article provides an introduction to the Limehouse Link, explaining some of the fundamental characteristics of its construction and position in London's urban landscape. More importantly, the article then considers how one might understand an everyday yet monumental construction such as this: a tunnel without obvious aesthetic form, design intent or symbolic meaning, but which nonetheless has an undeniable presence in the city. The Limehouse Link is therefore interpreted in terms of the car driver's immersive experience of the tunnel, more active constructions of this experience through sensory qualities of sound, representations of the tunnel in different media and art, ways of knowing the history of Limehouse, and, in particular, as a kind of aesthetic experience. The article concludes that driving through the Limehouse Link is to engage in a different way of knowing the postmodern city.     

The Limehouse Link: the architectural and cultural history of a monumental road tunnel in London's Docklands

In the Docklands area of London lies the ‘Limehouse Link’, a dual-bore road tunnel used by around 80,000 cars each day. A monumental and highly expensive piece of construction, the Limehouse Link has nonetheless received almost no attention from architectural historians or others concerned with the history of construction, engineering or urban development.

This article provides an introduction to the Limehouse Link, explaining some of the fundamental characteristics of its construction and position in London's urban landscape. More importantly, the article then considers how one might understand an everyday yet monumental construction such as this: a tunnel without obvious aesthetic form, design intent or symbolic meaning, but which nonetheless has an undeniable presence in the city. The Limehouse Link is therefore interpreted in terms of the car driver's immersive experience of the tunnel, more active constructions of this experience through sensory qualities of sound, representations of the tunnel in different media and art, ways of knowing the history of Limehouse, and, in particular, as a kind of aesthetic experience. The article concludes that driving through the Limehouse Link is to engage in a different way of knowing the postmodern city.     

沉管隧道注浆效果监测与评价的试验研究

为了探索沉管隧道管底注浆效果的监测方法和评价体系,在国内率先采用探地雷达和数字地震仪对舟山沈家门港海底隧道模型的注浆基础进行了测试研究。通过在注浆前、注浆过程中以及注浆完成2小时后所进行的现场检测,将采集到雷达波形和面波波形与模型中预先设置的观察窗现场观察的结果进行对比,确定注浆前、注浆过程中、注浆完成后三个阶段的典型波形,以判别和评价沉管隧道管底注浆基础效果。试验结果表明,探地雷达结合面波法的监测方法能作为在管底注浆施工时的停止注浆条件之一,可满足沉管隧道现场施工时管底注浆基础效果的监测和评价,进而可为沉管隧道的工程设计方案提供依据。     

沉管隧道基础注浆效果模拟试验研究

随着城市交通的快速发展,在跨海、跨江等工程中逐渐引入了沉管隧道施工,但也出现了基础不均匀沉降、灌浆不严实等问题。针对海底沉管隧道基础注浆过程,浆液流动特性、注浆充填效果评价等复杂技术问题,以舟山沈家门港海底隧道工程为背景,采用1:10相似模型试验方法系统研究了在设定注浆压力条件下浆液流动特性以及不同垫层粒径、不同垫层坡度和不同淤泥厚度的影响。在此基础上根据相似原理将模型试验结果合理拓展,建立了实际工程条件下基槽灌浆扩散半径、注浆压力与时间的相关关系,以期为沉管隧道工程设计和施工提供依据。     

Transport of tunnel elements from Baltimore to Boston, over the Atlantic Ocean

A new immersed tube tunnel has recently been built in Boston as part of the city's Central Artery project. Because part of the construction took place in Baltimore, the elements needed to be transported by sea to Boston. Several options were possible. The engineering behind the choice of transport is explained.     

Developments in immersed tunnelling in Holland

Holland has 22 immersed tunnels (14 road, 5 rail and 3 utilities tunnels). Another three are under construction, and more are foreseen. The tunnels are of the concrete type, i.e., constructed without a steel shell. The paper describes developments in technology and in design philosophy since the first immersed tunnel was completed 52 years ago. These developments include, amongst others: the introduction of the Gina rubber gasket between elements; the division of elements into sections divided by flexible joints; the application (if possible) of longer elements (up to 268 m); the use of precast sections for tunnels that have a small cross-section; the omission of the watertight lining (made possible by cooling the concrete of the walls during the first days after pouring); various foundation methods (e.g., sand flow instead of sand jet system; piled foundations when necessary); the use of the excavation for the open ramps (or the part of the tunnel built on land) as a casting basin for the elements; the changed approach to casting basins now that well pumping is usually forbidden; and the transport of the elements across shallow locations and across the sea. It is emphasized that the current state of immersed tunnel technology is the result of a continuous international exchange of ideas and experiences.     

Sydney Harbour Tunnel—Driven and Cut-and-Cover Tunnels

The paper describes the design and some construction aspects of the land tunnel approaches to the immersed tube crossing of the Sydney Harbour. Discussion is included on tunnel layout, excavation methods and order and method of working, primary and final ground support, concrete structures and filler wall construction. Durability aspects—i.e., groundwater, seepage, cocrete quality and membranes—are also presented. Monitoring results to date are also discussed.     

过江隧道混凝土沉管预制新技术

越来越大的运用需求和跨越更大水深、更宽阔海峡的发展趋势,使混凝土沉管隧道的传统预制技术面临许多挑战。发展更高效率、更灵活和更可靠的预制技术具有重大意义。结合典型工程实例,阐述混凝土沉管的预制新技术:移动干坞技术,分部浮态浇注技术,工厂化、全断面节段浇注技术。分别介绍了各预制方法的技术特点、施工工艺、优势及不足。新技术的应用发展和丰富了沉管隧道的设计和施工技术。     

Single-shell In-situ concrete tunnel lining: Experience in the Federal Republic of Germany

Although traffic tunnel construction in West Germany typically has used in-situ concrete as a double-shell lining, this method is both time-consuming and costly to apply. Recent research efforts have focused on the possibilities of single-shell in-situ concrete tunnel lining. This paper describes tests performed recently in West Germany on the use of (1) shotcrete and (2) steel-fibre-reinforced pumped concrete. The discussion deals with problems involved in these types of construction, the site and laboratory tests performed, and recommendations/prospects for application of these types of tunnel linings. The article also reports on two recent research projects, involving: (1) tunnel lining for large cross-sections with steel plate skin and unreinforced backfill concrete; and (2) construction and economic possibilities for creating tunnels in monocoque design.     

A milestone in tunnelling: Rotterdam's Maas tunnel celebrates its fiftieth anniversary

Built 1937-42 in Rotterdam, Holland, the Maas River Tunnel was the first immersed road tunnel in the world with a rectangular cross-section, constructed in reinforced concrete. On the occasion of the 50-year anniversary of this milestone in Tunnelling, T&UST is devoting this commemorative article to the subsequent development of the immersed tube technique. Based on their personal experience, the authors recall the innovative design and execution process, and the dramatic circumstances during World War II that characterized the Mass Tunnel project. A brief review is given on the further, worldwide development of immersed tunneling that resulted from the achievements on the Mass Tunnel pilot project.     

Challenges and strategies involved in designing and constructing a 6 km immersed tunnel: A case study of the Hong Kong–Zhuhai–Macao Bridge

A 6 km immersed tunnel of the Hong Kong–Zhuhai–Macao Bridge (HZMB) has been designed and funded. Once completed in 2016, the HZMB Tunnel will break the record of the 5.8 km BART Tunnel in the United States, although it will soon be overtaken by the ∼20 km Fehmarn Tunnel between Denmark and Germany that is to be completed in 2020. Construction of the HZMB Tunnel was started in 2011 and more than ten elements thus far have been installed on the site. This paper presents details about the challenges and solutions for the design and construction of the HZMB Tunnel on a strategic level. Special features of the HZMB Tunnel include a long length of 6 km, a deep water depth of almost 45 m, and a thick backfill of 23 m. Challenges include severe marine environment, strict requirements for waterproofing, construction of sections connecting the tunnel with artificial islands, and tunnel stability after future excavation of fairway trenches. Moreover, the HZMB Tunnel is challenged by possible sand liquefaction in seismic events, conservation of white Chinese dolphin, and waterway dispersion during construction. Details about the strategies are given in order to improve the immersed tunnel design and construction methods.     

沉管隧道半刚性管节节段接头力学性能数值模拟

接头是沉管隧道受力最薄弱的环节。依托实际工程建立了沉管隧道节段接头三维数值模型,研究了沉管隧道半刚性管节节段接头抗弯及抗剪力学性能,得到了接头受力与变形规律及接头抗弯、抗剪刚度变化规律。研究结果表明：(1)在压弯工况下,节段接头张开量与接头弯矩关系呈现三阶段变化规律,当接头张开量小于0.1 mm时,其抗弯刚度约占本体刚度的49%～87%,当接头张开量大于1 mm时,其抗弯刚度不足本体刚度的10%,初始预应力损失导致接头抗弯性能降低;(2)压剪工况下的接头抗剪性能主要由节段之间端面混凝土摩擦力提供,设置剪力键传力垫层可充分发挥节段接头端面混凝土摩擦抗剪力,提高接头整体抗剪性能;(3)在压弯工况下传力垫层不影响接头转动,而弯剪受力模式降低了传力垫层总受压荷载。     

Steel-shell immersed tunnels- Forty years of experience

The author traces his forty years of experience in immersed tunnel design and construction. The paper provides a brief history of of immersed tunnel technology from its beginnings in the early nineteenth century, and describes some of the major developments that have improved immersed tunnel design and construction methods. In a number of cases, immersed tunnelling techniques are related to the submerged floating tunnel (SFT) concept. The paper also relates some case histories of unforeseen problems that have occurred in the construction of some immersed tunnels.