Journal articles
Author(s) | Title | Journal | Issue | Page | Category |
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Bacher, Michael; Nipitsch, Gernot; Fruhwirt, Daniel; Sturm, Peter | Semmering Base Tunnel - Keeping shafts free of ice through the example of the Fröschnitz 2 supply shaft / Semmering-Basistunnel - Eisfreihaltung von Schächten am Beispiel des Versorgungsschachts Fröschnitz 2 | Geomechanics and Tunnelling | 6/2019 | 631-637 | Topics |
AbstractThe Fröschnitz 1 and Fröschnitz 2 supply shafts of the Semmering Base Tunnel are used for the ventilation of the tunnel drives, transport of personnel, materials and machinery and as escape and rescue routes. Until the final completion of the concrete inner lining in the shafts, water still emerges repeatedly at the surface at a few locations of the shotcrete support layer. This led above all for the Fröschnitz 2 shaft to ice formation during longer periods with outside air temperatures below the freezing point of water with simultaneous operation of the fresh air supply. The effectiveness of warm air supply was investigated with thermodynamic and aerodynamic investigations and then the cost-effectiveness of two selected systems to provide warm air were considered. The aerodynamic simulations showed that in particular the entry angle of the warm fresh air flow is decisive for the magnitude of the warm air losses. x | |||||
Cordes, Tobias; Weifner, Tassilo; Unteregger, David; Bergmeister, Konrad | Interaction between deep tunnel drives and an existing tunnel in fault zones - Modelling against reality / Wechselwirkungen zwischen tiefliegendem Tunnelvortrieb und bestehendem Tunnel im Bereich von Störzonen - Modellierung versus Realität | Geomechanics and Tunnelling | 6/2019 | 641-650 | Topics |
AbstractThe influence of a tunnel drive on an existing tunnel is primarily the result of the tunnel geometries, the relative location of the two tunnels, the geological-geomechanical conditions and the associated primary stress state. During construction of the Brenner Base Tunnel, there are constructionally relevant interactions in some places between the running tunnels and the exploratory tunnel (EKS) running centrally and 12 m deeper. The rock mass stress as a result of driving the running tunnels here leads to deformations of the previously driven exploratory tunnel. Due to the high loading on the outer linings of deep tunnels and the high stiffness of the already hardened shotcrete support, slight deformation can cause local cracking in the support layer. This article compares the observed deformations in a fault zone intersecting at a flat angle with numerical simulations, which enables investigation of the geomechanical problems. Comparison of the calculation results with the real deformation behaviour permits the validation of the numerical simulations and the reliability and limits of such analyses. x | |||||
Diernhofer, Florian; Schneider, Klaus; Steiner, Helmut | Challenge of maintaining the Koralm Tunnel - Balancing operational availability and increasing railway equipment / Herausforderung Instandhaltung Koralmtunnel im Spannungsfeld betrieblicher Verfügbarkeit und Anlagenmehrung | Geomechanics and Tunnelling | 6/2019 | 652-660 | Topics |
AbstractThe Koralm Tunnel (length 33 km) crossing the eastern Alps is part of the Koralmbahn line and one of the longest rail tunnels in the world. The installation of railway equipment in the tunnel is due to start soon and it is particularly important to now make current decisions considerung future developments and demands. In particular the conflicting goals of the scheduling horizon of the construction permit process nearly 20 years ago, the 150-year design horizon and the rapid development of electronics, data processing and telematics have to be considered. Experience of operation of long rail tunnels confirms that despite all logistical efforts, the maintenance of railway equipment leads to a great expense of time and finance and also to restrictions of the line availability for operations. x | |||||
Geißler, Hendrik; Lassnig, Herbert | Dewatering of sludges from aggregate production / Entwässerung von Schlämmen aus der Produktion mineralischer Zuschlagstoffe | Geomechanics and Tunnelling | 6/2019 | 661-666 | Topics |
AbstractIn order to implement construction projects responsibly and at the same time efficiently, intelligent, multi-project material flow management is becoming ever more important. At the Brenner Base Tunnel, material excavated from the tunnel and geogenic fill was processed for use as concrete aggregates. One part of this processing was the separation of the finest grains by washing the material. This however produced a considerable quantity of sludge, which was to be dewatered immediately after the washing. The article describes the sludge dewatering in geotextile tubes. In addition to the application example from the construction of the Brenner Base Tunnel, the findings from this project have also been applied to optimise dewatering systems in the original application area of cleaning up waterways. Finally there is a brief outlook of current research results regarding the use of the dewatering system for used bentonite suspensions in specialised civil engineering. x | |||||
Gschwandtner, Gunter Gernot; Lenz, Gerold; Wagner, Oliver Kai | Collapses in the vicinity of fault zones - Geotechnical causes and identification / Nachbrüche im Nahbereich von Störungen - Geotechnische Ursachen und Identifikation | Geomechanics and Tunnelling | 6/2019 | 667-673 | Topics |
AbstractThe Semmering Base Tunnel with a total length of 27.3 km is being excavated from the Gloggnitz portal as well as from three intermediate faces at Göstritz, Fröschnitzgraben and Grautschenhof. The geological conditions of the project are characterized by tectonically extremely complex rock formations with difficult geotechnical conditions. The excavation passes through numerous fault zones with deep overburden. During the excavation works, some large-volume collapses occurred. In this article, the collapse events are reconstructed from the available geological and geotechnical information. The reconstruction of the observed system behaviour is based on analytical and numerical calculations. The aim is to identify the respective failure mechanisms. x | |||||
Kessler, Gernot; Klais, Frank; Reiterer, Markus | Site facilities on contract SBT 3.1 / Die Bauinstallationen im Baulos SBT 3.1 | Geomechanics and Tunnelling | 6/2019 | 674-680 | Topics |
AbstractOn contract SBT3.1 of the Semmering Base Tunnel, the intermediate access point at Grautschenhof had to be relocated late in the tender design phase due to new geological findings. One consequence of this was the limited space available on the new construction site area. A number of complementary measures were considered by the client in the tender. Supplemented by innovative technical solutions from the SBT 3.1 Grautschenhof joint venture, it was possible to establish a functioning logistics system for four conventional excavations in the tightest of spaces. x | |||||
Klaffenböck, Thomas; Gertl, Reinhard | Automatic fire-fighting systems in tunnels / Automatische Brandbekämpfungsanlagen in untertägigen Bauwerken | Geomechanics and Tunnelling | 6/2019 | 681-689 | Topics |
AbstractA fire can occur in many areas of a transport system. Detecting fires at an early stage and rapid automated fire-fighting can significantly minimize or completely prevent damage to rolling stock and infrastructure. In addition to effective fire-fighting, people should be safeguarded, the systems should be economical, and activation should cause a minimum of damage. Despite the positive effects of using automatic fire-fighting systems in terms of building protection and reducing the fire load, there may be negative effects on escaping persons during the escape phase. Different systems such as the high-pressure water mist system and the deluge system are investigated by CFD simulation and evaluated with regard to their use during the escape and external rescue phases. x | |||||
Pfeffer, Robert; Rohm, Paul; Oppitz, David | Directional drilling on construction section SBT3.1 - the challenge of drilling speed and accuracy / Gerichtete Vollbohrung am Baulos SBT3.1 - Herausforderung Bohrgeschwindigkeit und Richtungsgenauigkeit im Störzonenbereich | Geomechanics and Tunnelling | 6/2019 | 690-694 | Topics |
AbstractThe Semmering Base Tunnel is being built by Austrian Federal Railways as part of the upgrading of the southern railway line. On contract SBT3.1, Züblin Spezialtiefbau Ges.m.b.H. was employed to undertake slope stabilization, piles dia. 1,500 mm embedded into the rock, as well as vertical and horizontal boreholes in the fault zones of Semmering. Due to the high requirements on drilling speed and accuracy of the boreholes, they were drilled as directional drilling with a hydraulic down-the-hole hammer. The vertical holes were used to install sleeve pipes for grouting works for the shaft Sommerau 2. The horizontal holes, also planned for the inclusion of sleeve pipes for grouting works, were used after on-site rescheduling during the project for exploration and drainage of the rock mass. The drilling and survey data were subject to continual and thorough review to increase the efficiency of each control operation. x | |||||
Pointner, Peter; Höfer-Öllinger, Giorgio | Geological tests on site / Baubegleitende geologische Untersuchungen | Geomechanics and Tunnelling | 6/2019 | 695-701 | Topics |
AbstractIn addition to laboratory analysis, tests can be carried out on site to support the geological underground documentation. They should cover the important parameters on the project and be easy and time-saving to implement. This article describes a selection of methods and their suitability for use on construction sites. The tests comprise determination of water content, grain size distribution as well as the implementation of point load and Cerchar abrasiveness tests. For all these tests, the practical application on the site of the Koralm Tunnel contract KAT 3 and implementation details are explained. For all on-site tests, it is recommended that the results gained should be compared with the experimental procedure and the results of laboratory analyses. x | |||||
Pichler, Moritz; Fürnschuß, Martin; Friedl, Katrin; Schürhuber, Robert; Schmautzer, Ernst | Electrical earthing in sub-surface projects / Elektrische Erdung bei untertägigen Infrastrukturprojekten | Geomechanics and Tunnelling | 6/2019 | 702-707 | Topics |
AbstractElectrical earthing (grounding) is necessary for the proper operation of electrical systems, machines and electronic equipment in the event of a fault, for protection against lightning and personal injury, and for reasons of electromagnetic compatibility. Earthing is understood as “making an electrical connection between a given point in a system or in an installation or in equipment and a local earth”. Electrical grounding systems are designed according to national and international standards, with some of these standards occupying a significant place in the legal hierarchy in Austria and being binding. Simple structures are designed using approximate formulas given in the literature and standards; more complex arrangements use programs with analytical or numerical models for the calculation and design of grounding systems. Underground infrastructure projects require additional considerations. Starting with the technical and legal requirements, the typical process steps for the design of electrical grounding systems are shown. x | |||||
Mössmer, Stefan; Sulzbacher, Gerhard; Jedlitschka, Gernot; Holzleitner, Wolfgang | Brenner Base Tunnel - Tunnelling in the immediate vicinity of existing structures on the Tulfes-Pfons contract / Brenner Basistunnel - Vortrieb im unmittelbaren Nahbereich von Bestandsbauwerken im Baulos Tulfes-Pfons | Geomechanics and Tunnelling | 6/2019 | 708-715 | Topics |
AbstractThis report deals with tunnelling over and under existing tunnels with unreinforced concrete linings and tunnelling under an existing tunnel only supported with shotcrete. The uppermost task was to avoid damage to the existing tunnel and this could be fulfilled through carefully staged advance steps, technically correct construction by the contractor and a dense observation network. The experience tunnelling over an existing tunnel supported only with shotcrete shows that despite slight deformation, cracks and spalling occurred to the shotcrete support layer of the tunnel beneath. This damage did impair the serviceability of the support layer although the structural safety of the tunnel was never in danger. The impairment of the serviceability was temporary and could be remedied by installing overhead protection. In the long term, repair measures were necessary to the support layer in zones with poor geological conditions. x | |||||
Erharter, Georg H.; Poscher, Gerhard; Sommer, Peter; Sedlacek, Christoph | Geotechnical characteristics of soft rocks of the Inneralpine Molasse - Brenner Base Tunnel access route, Unterangerberg, Tyrol, Austria | Geomechanics and Tunnelling | 6/2019 | 716-720 | Topics |
AbstractThe engineering geological investigation for the environmental impact assessment of the more than 20 km long route section Schaftenau-Radfeld in the Lower Inn Valley (Tyrol) was conducted in 2017/18. As a central structure, a nearly 3 km long tunnel will be built through the Unterangerberg. The bedrock of the Unterangerberg consists of turbiditic, marine deposits of the Inneralpine Molasse with interbedded layers of marl, claystone and sandstone. The proximity to the Inntal shearzone and exogeneous effects like several glaciations have softened the surface of the inherently weak bedrock and led to heterogeneous mechanical properties. The monotonous lithology is therefore accompanied by an inhomogeneous rock mass characterization. This paper describes experiences of the geotechnical investigation of this weak rock. It was observed that only a quick transport of samples from the drilling site to the laboratory can guarantee for test results in accordance with the standards. The results, lying in the transitional zone between soft rock and hard soil, are in good accordance with data from other studies. x | |||||
Flora, Matthias; Goliasch, Robert; Strauss, Armin; Atzori, Denis | Hard rock tunnel boring machines - State of the art 2020 / Tunnelbohrmaschinen für Hartgestein - Stand der Technik im Jahr 2020 | Geomechanics and Tunnelling | 6/2019 | 721-729 | Topics |
AbstractAt this year's International Planning Design and Construction (IPDC) Workshop of the Unit of Project and Construction Management (i3b) of the University of Innsbruck, a selected group of tunnelling engineers took a closer look at the state of the art of hard rock tunnel boring machines and the challenges of tunnelling systems along the Brenner axis. The three currently active construction contracts using mechanized tunnelling technology at the Brenner Base Tunnel have an intersection of comparable geological/geotechnical conditions (quartz phyllite, schist, gneiss and granite) and yet different machine types were selected: a Gripper TBM for the Tulfes-Pfons exploration tunnel - H33, three Double Shield machines for the Mauls 2/3 contract and four Single Shield machines for contract H51. The focus of this workshop was accordingly: from geology/geotechnics to the key specifications of the TBM as a basis, followed by the consideration of the type-independent TBM parameters, the differences as well as advantages and disadvantages of the three machine types and finally an outlook into the future regarding further developments and need for innovation. This article summarizes the contents of the workshop. x | |||||
Hammer, Anna-Lena; Thewes, Markus; Galler, Robert | Empirical forecasting model to determine the strength development of shotcrete / Empirisches Prognosemodell zur Bestimmung der Festigkeitsentwicklung von Spritzbeton | Geomechanics and Tunnelling | 6/2019 | 730-738 | Topics |
AbstractShotcrete is an essential support element in tunnelling. From the start of the hydration of shotcrete, it resists stresses and deformation. Therefore its time-dependent material properties, in particular the strength development and stiffness development, are significant. With time, the early strength can affect the progress of rock pressure and the support resistance. In order to describe its mechanical material properties, there are models, mostly validated with data from dry-mix shotcrete or older shotcrete mix designs. Continuous further development in additive technology has however considerable improved the performance of shotcrete in recent years. In this article, data from more recent test series and from practical projects are evaluated. Building on the evaluation of the strength curves, an empirical forecasting model is presented, which can be used for the qualitative estimation of shotcrete strength development. x | |||||
Schiller, Andreas; Wiest, Marius | Development of a new high-strength SN anchor for the optimization of conventional tunnelling / Entwicklung eines neuen hochfesten SN-Ankers zur Optimierung von konventionellen Vortrieben | Geomechanics and Tunnelling | 6/2019 | 739-744 | Topics |
AbstractThe new high-strength SN anchors offer easy handling resulting from a 44 % weight saving compared to conventional SN anchors with the same structural properties. In addition to the advantages in handling and occupational safety, consequential economic advantages can of course be mentioned such as lower freight costs, the option of reducing the borehole diameter, the possibility of parallel execution of various work steps and, finally, optimization of speed in conventional tunnelling. x | |||||
Kumpfmüller, Sebastian; Feiersinger, Andreas; Doulkas, George | Sprayed concrete lining - Improving safety through design | Geomechanics and Tunnelling | 6/2019 | 745-750 | Topics |
AbstractIn-depth contractor engagement during the concept and detailed design phases of the Bank Station Capacity Upgrade project led to an optimised tunnel design with significant improvements in risk management. Regular, coordinated meetings between the design and construction teams led to innovative construction solutions utilised in eliminating risks where possible and where not possible, controlling them through best practice. This paper outlines the lessons learnt from other tunnelling projects in London and presents how the risks related with SCL works have been dealt with in the tunnels design for the Bank Station Capacity Upgrade project. x | |||||
Nebois, Christian; Gartner, Ilse; Herzfeld, Thomas | Vienna Underground, Neubaugasse Station - Preparatory works and challenges on the surface / U-Bahn Wien, Station Neubaugasse - Vorarbeiten und Herausforderungen an der Oberfläche | Geomechanics and Tunnelling | 5/2019 | 417-423 | Topics |
AbstractThe U2 station Neubaugasse will become one of the busiest interchange stations in the Vienna underground network, with passengers changing between the existing line U3 running along under the Mariahilfer Straße and the new line U2 crossing the Mariahilfer Straße. The Mariahilfer Straße, one of the best known shopping streets in Vienna with shopping centres and high numbers of passers-by in the middle of a densely built-up residential area, and its side streets have been redesigned in the last few years with the aim of traffic calming and creating new public spaces. x | |||||
Schmeiser, Josef; Hoppe, Peter; Theiss, Reinhold | Technical and logistical challenges of the construction of the Museumsinsel Station in Berlin / Technische und logistische Herausforderungen beim Bau des Bahnhofs Museumsinsel in Berlin | Geomechanics and Tunnelling | 5/2019 | 426-433 | Topics |
AbstractThe closing of the gap in line U5 of the Berlin underground completes the missing connection between the Alexanderplatz and Brandenburger Tor stations. The existing line U5 currently ends at the Alexanderplatz. With the closure of the gap, the existing tunnels at the Berliner Roten Rathaus will be connected to the Brandenburger Tor station on the line U55. The project includes the construction of three new underground stations and two single-track tunnels connecting them, which are being tunnelling by shield machines. The new alignment thus passes deep under the city, under the River Spree, the new Berliner Schloss and the Spreekanal as well as running along beneath the street Unter den Linden to the Brandenburger Tor. The construction activities are taking place right in the centre of Berlin and the particular local conditions are a logistical and technical challenge. x | |||||
Zeidler, Kurt; Gall, Vojtech | Modern urban tunnelling - Responding to social needs | Geomechanics and Tunnelling | 5/2019 | 434-439 | Topics |
AbstractUrban Tunnelling requires handling of a wide range of ground conditions and multiple challenges generated by work access constraints, settlement sensitive structures, as well as testing socio economic needs such as limitations to noise and dust emissions as well as impact on traffic. Such projects and their bespoke technical solutions come at a price. The realisation of large-scale urban infrastructure projects is often accompanied by intensive discussions about the cost in support of the social need for such projects. This article provides socio-economic reasoning for major urban infrastructure projects and insight in selected technical solutions that are required to realise these projects in urban settings. x | |||||
Urschitz, Gerhard J. | At the Limit - Soft-ground tunnelling under the city highway of Toronto / Am Limit - Lockergesteinsvortriebe unter der Stadtautobahn von Toronto | Geomechanics and Tunnelling | 5/2019 | 440-449 | Topics |
AbstractDuring the Design-Build-Finance procurement of the “RER Highway 401 Rail Tunnel”, the option with two single SEM tunnels was selected as preferred alternative. The challenges of this project lie not only in the conditions and requirements by the Ministry of Transportation of Ontario, the owner of the highway above and the existing tunnel beside the new tunnels, but also in construction beneath one of the busiest highways in North America. Pre-support measures for tunnel excavation, which cannot involve any type of grouting directly beneath the roadway surface, were evaluated based on their risk exposure, resulting in the selection of a pipe jacked umbrella above the tunnel crowns. A sophisticated monitoring programme is implemented with online access at any time to allow for immediate response and implementation of pre-determined mitigation measures as required. x | |||||
Laubbichler, Jürgen; Schwind, Thomas; Karner, Christian; Gakis, Angelos | Innovative NATM solutions for major subway stations in North America - An overview of recent developments and project case histories | Geomechanics and Tunnelling | 5/2019 | 450-455 | Topics |
AbstractSince the first mined subway stations were constructed in Washington, DC in the mid-80s, European engineers and construction professionals have been promoting the benefits of the conventional tunneling method for major urban infrastructure projects throughout North America. In recent years, significant advances have been made in the use of numerical design tools, innovative construction approaches, fiber reinforced shotcrete mixes and the increased use of robotics and laser-scanning equipment. This article provides an overview of key technologies and innovations applied on recent projects, including Chinatown Station in San Francisco; Parliament, Lyon and Rideau Stations in Ottawa; and Laird, Avenue and Oakwood Stations in Toronto. x | |||||
Lienhart, Christoph; Chiaverio, Flavio; Rauscher, Wolfgang; Kurtz, Matthias | Feuerbach and Bad Cannstatt Tunnels - special requirements of the inner-city Location and difficult geotechnical Conditions / Tunnel Feuerbach und Bad Cannstatt - spezielle Anforderungen bei innerstädtischer Lage und schwierigen geotechnischen Verhältnissen | Geomechanics and Tunnelling | 5/2019 | 456-466 | Topics |
AbstractThe Feuerbach and Bad Cannstatt Tunnels on the Stuttgart 21 project are two central elements of the future Stuttgart inner-city rail node. Due to the central location in the middle of Stuttgart, there are particular requirements for construction operations and logistics. These effects are additionally reinforced by the very difficult geological and geotechnical conditions in the valley of Stuttgart: very changeable strengths of the prevailing formations of the gypsum Keuper, sometimes with shallow overburden with dense building and roads above. The tunnel also passes through sections with anhydrite content, which tends to swell on contact with water. In this paper, both the challenges of the inner-city location are described and the methods and solutions used to counter an impairment of structural safety and serviceability in the anhydrite sections. x | |||||
Schachinger, Tobias; Arbeiter, Florian J.; Eichinger, Stefanie; Saliger, Florian | Research on pipe materials for tunnel drainage by the ÖBB Task Force Drainage / Forschung der ÖBB-Task Force Drainage zu Rohrmaterialien der Tunnelentwässerung | Geomechanics and Tunnelling | 5/2019 | 467-471 | Topics |
AbstractDue to the additional tunnels that are currently under design or construction, drainage maintenance costs are expected to rise significantly over the next few years. An increased amount of maintenance will also be necessary due to older drainage pipes damaged during intensive cleaning and flushing. To counter these problems, an internal task force for drainage pipes has been installed within the ÖBB. Together with research institutions from several fields of science, projects are being carried out to find ways to decrease the overall maintenance effort. Topics include screening of possible rehabilitation methods for damaged pipes, and investigation of currently used materials with regard to their mechanical suitability. A multi-disciplinary research topic has also been initiated to investigate the potential of material modifications with the goal to decrease overall precipitation in drainage pipes and associated maintenance. First results on modified materials already show potential to decrease calcite precipitation. x | |||||
Erharter, Georg H.; Marcher, Thomas; Reinhold, Chris | Application of artificial neural networks for Underground construction - Chances and challenges - Insights from the BBT exploratory tunnel Ahrental Pfons | Geomechanics and Tunnelling | 5/2019 | 472-477 | Topics |
AbstractThe interaction of tunnel boring machines with the rock mass is highly influenced by human, technical and geological factors. Interpretation of geological observations and TBM data is currently done on a subjective basis. Technologies based on Artificial Intelligence research, can be used to automatically classify TBM data into rock mass behaviour types. Albeit first results look promising, any technology poses the threat of malicious use that deliberately harms / benefits one or another party. x | |||||
Bakhshi, Mehdi; Nasri, Verya | New ACI 533 guide on general design and construction aspects of precast concrete tunnel segments | Geomechanics and Tunnelling | 5/2019 | 478-483 | Topics |
AbstractAmerican Concrete Institute (ACI) is aiming to publish its first guide (ACI 533.2R) on general aspects of precast tunnel segments. This paper presents salient features of the guide including the most recent developments on major aspects of design, manufacturing and construction. This document is drafted based on the knowledge and the experience gained on projects in Asia, Europe, and North America, and available national and international recommendations. Procedures to perform structural design during production, transportation, construction and final service stages are explained. Details of segmental ring geometry and systems, concrete strength, curing, and reinforcement detailing are discussed. Gasket design, segment connection devices, anchorage systems, tolerances, measurement and dimensional control, and repair of defects are among other topics that are covered. This document also addresses durability and degradation mechanisms of tunnel linings and their mitigation methods. While some parts of this guide may only consider the procedures adopted by ACI, they can be extended to other national and international codes and used worldwide. x |