Journal articles
Author(s) | Title | Journal | Issue | Page | Category |
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Flora, Matthias; Jäger, Manfred; Teuscher, Peter | Selection and specification of a tunnel boring machine as the leading factor for the achievement of project goals / Auswahl und Spezifizierung der Tunnelvortriebsmaschine als maßgebliche Einflussgröße für den Projekterfolg | Geomechanics and Tunnelling | 5/2018 | 492-504 | Topics |
AbstractFor almost all tunnelling jobs in the world - independent of continent or culture - the question has to be answered, which is the most suitable tunnelling method or in case of a mechanised tunnelling project the preferred tunnel boring machine to be used. Just the correct choice of a machine does not necessarily lead to the success of a project, which depends more on the design of the tunnel boring machine as well as the definition of measures to cope with all possible events during the advance. The core of the article constitutes a priori determined decision-making process and the resulting guideline and intends to raise awareness of the critical criteria and parameters. x | |||||
Bach, Dietmar; Holzer, Wolfgang; Leitner, Wolfgang; Radoni , Nedim | The use of TBM process data as a normative basis of the contractual advance classification for TBM advances in hard rock / Die Verwendung von Maschinenparametern und Betriebsdaten als normative Grundlage für die vertragliche Vortriebsklassifizierung für Tunnelvortriebsmaschinen im Festgestein | Geomechanics and Tunnelling | 5/2018 | 505-518 | Topics |
AbstractIn April 2016 a newly formed working group began with the revision of the Austrian standard ÖNORM B 2203-2. The goal of the group was the establishment of a practicable advance classification scheme, which would be applicable both for the design and for the construction phase. In addition, a clear separation should be established between a regular advance, which is clearly described and can be calculated by the bidding contractor, and a “hindered advance”, which cannot clearly be described and calculated. The contractual framework is used to compensate for the regular advance, and hindering occurrences such as water ingress or increased wear are compensated by additional contractual time-dependent costs. Fair compensation regulations for hindered advance (such as an advance through blocky rock mass, mixed face conditions, swelling, squeezing ground, major face instabilities, increased adhesion and stickiness of muck, obstacles and suspension losses) are to be defined as well. The method presented in this paper and based on systematic TBM data evaluation achieves both the goal of contractual advance classification and the goal of establishing a simple threshold differentiating regular advance and hindered advance. x | |||||
Mair am Tinkhof, Kurt; Radon i , Nedim; Reinhold, Chris; Insam, Romed; Rehbock-Sander, Michael | From the geological prognosis to the TBM drive: Planning the main construction lots of the Brenner Base Tunnel / Vom geologischen Gutachten zum maschinellen Vortrieb: Festlegung des Vortriebskonzepts für die Hauptbaulose des Brenner Basistunnels | Geomechanics and Tunnelling | 5/2018 | 519-529 | Topics |
AbstractIt is state of the art to drive long tunnels in Alpine areas using hard rock TBMs. Mechanised tunnelling has much less flexibility than conventional excavation, so a deeper analysis of the available geological and geotechnical fundamentals is needed. In the course of planning the mechanised drives of the main tunnels on the Austrian side of the Brenner Base Tunnel, a detailed tunnelling concept was created, which deals with the project-specific features and boundary conditions. The exploratory tunnel, which is used for geological and geotechnical exploration for the construction of the main tunnels, is currently being excavated. Through additional analyses, the geotechnical model could be verified and a reliable update of the rock parameters and the associated critical decisions has been achieved. All further specifications regarding TBM requirements, additional and auxiliary measures, support concept, bill of quantities and construction time model were based on the prognosis of system behaviour. x | |||||
Cudrigh-Maislinger, Susanna | 3D geological modelling - Through the example of Karawanken Tunnel project, northern section / Geologische 3D-Modellierung am Beispiel des Karawankentunnels, Abschnitt Nord | Geomechanics and Tunnelling | 5/2018 | 530-536 | Topics |
AbstractBefore design and construction, particularly underground, it is essential to know the geological conditions well. Nowadays as in many other fields 3D modelling is a very powerful and helpful tool in geology and geotechnics. The advantages of 3D modelling in geology are convincing: In the past, 2D geological maps and sections were of common use and it could sometimes be difficult to conceive a 3D picture of the underground conditions from the 2D images. With modern software, geological 3D models can be generated easily. Once a 3D model is established, the underground situation is more comprehensible and inconsistencies in geological interpretation are immediately apparent. 2D sections can also be produced with little effort at any position. The model can also be used as a geological database for the project. All available geological and geotechnical information like maps, sections, borehole data and lab test results can be attached to the model. The generation of a geological 3D model will be explained through the example of the Karawanken Tunnel, northern section. x | |||||
Barth, Anton; Höllrigl, Jakob | Model adaption to reflect reality from design to construction through the example of a quarry / Anpassung der Modelle an die Wirklichkeit von der Planung zur Ausführung am Beispiel eines Steinbruchs | Geomechanics and Tunnelling | 5/2018 | 537-543 | Topics |
AbstractAfter a landslide in 2007, a quarry face is to be restored. Consequently, models had to be formed of the geological conditions, of the material behaviour and of the failure mechanism, as well as a calculation model to simulate this mechanism. The geological structure and observations during and after the landslide suggested that the failure was a result of the toppling of slab-shaped rock blocks. The landslide facilitated a back analysis of strength parameters from this large-scale in-situ test, thus making laboratory tests, derived from classification systems and estimations of these parameters, unnecessary. A limit equilibrium method and a numerical model available for the simulation of toppling correspondingly showed that flattening of the face up to the mining boundary results in a sufficient factor of safety. However, the transition from weathered material to rock could not yet be considered. Only the first step of the face restoration, and excavation of the weathered cover, managed to shed light on its thickness, which facilitated precision of the calculation model. Only the excavation of the rock mass displaced by the landslide will show whether the quarry face geometry necessary for a sufficient factor of safety is feasible with respect to the actual loosening of the rock mass and to the actual depth of the landslide. x | |||||
Brandtner, Markus; Hofmann, Matthias; Paternesi, Alessandra; Saurer, Erich; Schweiger, Helmut F.; Walter, Herbert | Design strategies for sprayed concrete linings / Bemessungsstrategien für Spritzbetonschalen | Geomechanics and Tunnelling | 5/2018 | 544-558 | Topics |
AbstractWith the introduction of Eurocodes, non-linear methods are now explicitly permitted for the determination of internal forces. Although the application of Eurocode 7 has not been intended for tunnel construction, it is applied in practice. Tunnel linings are treated as retaining structures in the sense of Eurocode 7. The choice of the Design Approach to be applied is specified in the National Annex (NA) of each country. The application of a standard to a field which was not intended for the purpose naturally leaves room for diverse interpretation. A working group was established by the Austrian Society for Geomechanics (ÖGG) to develop a consistent design strategy for tunnelling. Recommendations based on comparative calculations have been developed for the design of sprayed concrete linings. This article summarises the findings of the investigations carried out. x | |||||
Lenz, Gerold; Poisel, Alexander; Brandtner, Markus; Goricki, Andreas; Wagner, Oliver K. | Semmering Base Tunnel - Geotechnical models in design and construction / Semmering-Basistunnel - Geotechnische Modelle in Planung und Bau | Geomechanics and Tunnelling | 5/2018 | 559-565 | Topics |
AbstractThe article describes the fundamental geotechnical model assumptions in the design phase of the Semmering Base Tunnel. Two selected case studies show the verification of the geotechnical model during tunnel construction. The verification process is essentially based on geotechnical monitoring in combination with specific back analyses. It is shown that particularly in complex geotechnical conditions, such as deep tunnels in weak rock mass, the designer can only assess a range of expected behaviour. Most information about system behaviour and thus about the geotechnical model conceptions can only be gained during construction. An improved understanding of the geotechnical model provides the potential to identify and minimize geotechnical risks earlier and to adapt excavation and support measures to the actual conditions. x | |||||
Schneider-Muntau, Barbara; Reinhold, Chris; Cordes, Tobias; Bathaeian, Iman; Bergmeister, Konrad | Validation of longitudinal displacement profiles by measurement at the Brenner Base Tunnel / Validierung der Radialverschiebungen im Längsprofil durch Messungen beim Brenner Basistunnel | Geomechanics and Tunnelling | 5/2018 | 566-574 | Topics |
AbstractLongitudinal displacement profiles describe the displacement history during tunnel excavation, including that occurring ahead of the tunnel face. These deformations have an influence on the structural design of tunnel support. Theoretical approaches are used to estimate these deformations. However, as the approaches are based on assumptions, they should be applied with caution, particularly in case of deep tunnels. Therefore, experimentally determined longitudinal displacement profiles provide a valuable data basis for validation of the approaches. This study compares 40 m long horizontal chain inclinometer measurements in two lithologies in the exploration tunnel of the Brenner Base Tunnel with theoretically calculated profiles. The chain inclinometers were installed above the tunnel before the start of tunnelling. A measured radial displacement profile was created for each round, the statistical mean value curve was calculated and finally compared with the theoretical approaches. The measurement results show good qualitative agreement ahead of the tunnel face. x | |||||
Schubert, Wulf; Brunnegger, Stefan; Staudacher, Robert; Wenger, Julian | Further development of yielding elements and connecting elements for shotcrete / Weiterentwicklung von Stauchelementen und Spritzbetonanschlüssen | Geomechanics and Tunnelling | 5/2018 | 575-581 | Topics |
AbstractYielding elements in combination with shotcrete linings are used in Austria since 1994, replacing the previous method of leaving open gaps. The first system, used at the Galgenbergtunnel, consisted of groups of axially loaded steel pipes with manufactured local weakness. The resistance of those elements showed a pronounced oscillation during shortening. This triggered a first improvement of the elements in the late 1990ies. Those elements were called LSC (Lining Stress Controller) and subsequently successfully used on a significant number of projects around the world. Recently, the yielding elements have been further optimized aiming at easier production and lower costs. Still using steel pipes, those are filled with porous material, increasing the elements' capacity. With sequential excavation, construction joints in the shotcrete lining are necessary. Producing quality joints appears to be difficult without special connecting elements. The so produced connections are thus potential points of weakness, reducing the lining capacity. A prototype of a connecting element was developed, which can be easily produced and installed. Site tests have been successfully conducted at the tunnel Stein in Austria. x | |||||
Volkmann, Günther M. | Tunnel pre-support using pipe umbrellas - Technical developments and their advantages / Tunnel-Voraussicherung mit Rohrschirmen - Technische Entwicklungen und deren Vorteile | Geomechanics and Tunnelling | 5/2018 | 582-588 | Topics |
AbstractPipe umbrella support systems have been used successfully for tunnelling in challenging ground conditions since the 1970s. The single umbrella pipes are installed stepwise and parallel to the later installed saw-tooth shaped primary lining by connecting pipe pieces to each other. The connections are the weakest link of the support system, so recent developments in this field also have an effect on system performance. The development of both machinery and connection types have a major influence on pipe umbrella design for tunnelling. This includes not only simple parameters like installation length or tube dimension but also the connection type. So a conventional pipe umbrella design is not as cost-efficient as current technical possibilities allow, because material as well as time savings are missed. This article explains possible optimisations for pipe umbrella supported tunnels with simple examples to show cost-optimised design principles regarding time and material. x | |||||
Henzinger, Michael R.; Lange, Andreas; Volkmann, Günther M.; Moritz, Bernd A.; Schubert, Wulf | Bedding improvement of lining segments using geotextile tubes / Bettungsverbesserung von Tübbingringen mittels Geotextilschläuchen | Geomechanics and Tunnelling | 5/2018 | 589-598 | Topics |
AbstractDuring a shield TBM excavation in hard rock, the immediate backfill of the crown immediately behind the shield is technically difficult to realize. With the advance of the cutter head a relocation process of pea gravel within the annular gap is triggered, leading to an insufficient bedding distribution of the first segments behind the shield tail and to an ovalization of the segmental lining at a certain load level. During a test application as part of an “TBM research initiative” of the Austrian Federal Railways geotextile tubes were integrated into the exterior surface of the segments. Immediately after leaving the shield tail, the geotextile tube, which is placed all around one ring of segments, is expanded by injection with grout. As a result, an immediate bedding between the rock mass and segmental lining is established, also preventing the rearrangement of pea gravel within the annular gap when the shield is moved forward. The displacement measurements have shown that the ring of segments equipped with geotextile tubes experiences a more rigid body motion like behaviour after leaving the shield tail with a minimal ovalization only. Numerical simulations show the influence of bedding improvement on the ovalization of the ring of segments after leaving the shield tail. x | |||||
Thienert, Christian; Leismann, Frank; Edelhoff, Dennis; Valentini, Heiko; Hörlein, Norbert; Kleen, Eugen | Development of a water-permeable annular gap fill for single-shell drained segmental linings / Entwicklung eines wasserdurchlässigen Ringspaltmaterials für eine einschalige dränierende Tübbingbauweise | Geomechanics and Tunnelling | 5/2018 | 599-607 | Topics |
AbstractNowadays, tunnels with single-shell segmental lining are often constructed pressure-tight using gaskets. The economic application limit of this construction type is about 50 metres head of water. If the water pressure exceeds this value, considerably more complex - and thus more expensive - two-shell construction with an additional drainage layer between the inner and the outer lining is required. To extend the field of application of mechanized tunnelling with single shell lining in mid-mountain formations, an innovative approach was developed based on the application of a drainage layer in the annular gap fill with a water permeability kF <10-4 m/s. The basic idea of the newly developed water-permeable material for annular gap grouting is the use of a foam generator without a disturbing body, which foams the cement suspension in a defined way with sufficient compressive strength. Complex interrelations of material, process engineering and construction had to be considered comprehensively. The overall suitability of the developed process has been demonstrated in an extensive experimental program including field tests. The present paper focuses on the development of the construction material. x | |||||
Kohlböck, Bernhard; Griesser, Ewald; Hillisch, Stefan; Birgmann, Harald; Fasching, Alfred | The BIM pilot project Köstendorf - Salzburg / Das BIM-Pilotprojekt Köstendorf - Salzburg | Geomechanics and Tunnelling | 4/2018 | 325-334 | Topics |
AbstractThe new approx. 21 km long section between Köstendorf and Salzburg is one of the last major milestones in the upgrading of the Salzburg-Vienna rail corridor to four tracks. The section comprises a multitude of different civil engineering structures, posing high demands on the interdisciplinary design team. The open sections of the alignment require many over- and underpasses and road diversions. In addition, the majority of the section runs underground through the Flachgau Tunnel, which has the particular feature of a tunnel bridge. The aim of the BIM project is to provide a software-independent, integrated model of the whole project. All parties involved in the project collaborate to define the LOD for the terrain, existing building, land use and geological models, as well as the models for the proposed new infrastructure for the open section, tunnels, ventilation control building, bridges, civil structures and drainage. The LoD are defined in parallel with the AIA according to the KISTE infrastructure identification system used by ÖBB (Austrian Federal Railways). At the same time, the BIM execution plans are generated by the team and adapted to the new BIM processes. The opportunities provided by the element-based display and evaluation are anticipated to lead to considerable improvements in the field of interdisciplinary design and visualisation studies. The present article describes the current state of work and provides a preview of future developments. x | |||||
ibert, Marko; Lah, Martin; Saje, Samo | Challenges and opportunities in implementing BIM methodology in tunnelling | Geomechanics and Tunnelling | 4/2018 | 335-339 | Topics |
AbstractTunnelling differs fundamentally from mining, high rise buildings and civil surface construction in many ways, but when it comes to challenges, it combines the toughest from the three worlds. Tunnelling projects inherit uncertainties of ground conditions and constant preparedness for on-site changes from mining; complexity, dynamics and the need for detailing from buildings; and one of the challenges that tunnels inherit from civil surface construction is definitely the complex and curved geometry. To overcome the challenges and exploit the benefits of BIM methodology on tunnelling project it is essential to harmonize particles of existing standards, guidelines, processes and tools from the three worlds. x | |||||
Stelzer, Magdalena; Radoncic, Nedim; Iserte Llacer, Pedro Luis; Tatar, Ali; Holmberg, Mats | BIM processes and workflows using the example of the subway extension in Stockholm | Geomechanics and Tunnelling | 4/2018 | 340-347 | Topics |
AbstractThree major technical and economic factors of the “Yellow Line” project of the Stockholm subway network justify the decision to apply a BIM-oriented design: (1) Early optimization and risk minimization for cost and time and active counteraction to the loss of information throughout the entire lifecycle of the project, (2) all technical aspects are to be incorporated in the design simultaneously and from early stage onwards, (3) numerous surface and subsurface structures, including tunnels under operation and in vicinity of the new line lead to a complex geometrical layout and geotechnical influences on each of these structures are to be minimized. Commercial 3D/BIM products have proven to be developed for application in surface structure design and new methods had to be established to cope with high quality tunnel modelling, coordination and tunnelling challenges. This publication is addressing the experience and solutions made during the design: Choice of appropriate modelling tools, applied methodology for a structured design process in a multidisciplinary and manifold work environment, accounting to highly complex geologically-geotechnical data, seamless transfer of the model data to numerical analysis tools. The advantages and disadvantages of using BIM methodology are discussed and recommendations with regard to future development are presented. x | |||||
Exinger, Christoph; Mulitzer, Günther; Felsner, Rudolf; Lemmerer, Johann; Matt, Robert; Griesser, Ewald | BIM pilot project Granitztal tunnel chain - Development of data structures for tunnel structure and track superstructure / BIM-Pilotprojekt Tunnelkette Granitztal - Entwicklung von Datenstrukturen für den Tunnelrohbau und Oberbau | Geomechanics and Tunnelling | 4/2018 | 348-356 | Topics |
AbstractAn essential part of the Koralmbahn line, the Granitztal tunnel chain with a length of about 6.1 km runs between the Lavanttal and the Jauntal valleys and crosses the Deutsch Grutschen, the Granitztal and the Langer Berg. In early 2016, Austrian Railways ÖBB made a decision for the Granitztal tunnel chain project, which was then already under construction, to test the 3D model-based Building Information Modelling (BIM) design method in addition to conventional 2D design. One essential precondition for the application of the BIM method on transport infrastructure projects was recognised as the required data structures. In addition to the definition of general project requirements and standards for BIM, work started on the structuring and classification of the construction elements required for the tunnel structure and their properties. Of equal importance are the spatial positioning and location of the construction elements and the definition of topological relationships to each other. x | |||||
Frodl, Stephan; Mayer, Peter-Michael | BIM modelling in mined tunnelling / BIM-Modellierung im konventionellen Tunnelbau - Diskussion und Empfehlung für die zu berücksichtigende Bauwerksgeometrie in 3D-Modellen / Discussions and recommendation for the structural geometry to be considered in 3D models | Geomechanics and Tunnelling | 4/2018 | 357-365 | Topics |
AbstractIn the context of mined tunnelling, the excavation of the tunnel cross-section is performed with an overcut. The size of the required overcut depends on the expected rock deformation as well as on typical construction tolerances. Likewise, secondary linings are also built with an overcut in order to account for formwork deformation, construction tolerances and deformation due to ground loads. On the other hand, clients usually specify the nominal tunnel geometry, which differs from the overcut geometries previously mentioned. When designing a tunnel according to the BIM method, it should be clarified which geometry should be used to create the geometrical model, since deviations between the target and the overcut geometry can be considerable. To generate a drawing derived directly from the 3D BIM model for tunnel construction use, it is imperative that the geometrical model is created based on the overcut geometry. Only then can the reinforcement quantity or formwork be designed correctly. Only a model based on overcut geometries will yield the correct theoretical masses, which for example could be used for target-actual comparisons. This article outlines the basics of the current 2D design approach; its technical limits are presented and contrasted with the proposed 3D design model. The article further shows how a 3D BIM design model has to be created so that 2D drawings for construction can be derived or created from it. In addition, general recommendations are provided for creation of BIM geometrical models. x | |||||
Gruber, Christian; Weiner, Thorsten; Zuchtriegel, Ralf | BIM for tunnelling for a company- Approaches and strategies / BIM im Tunnelbau aus Sicht eines ausführenden Unternehmens - Herangehensweise und Herausforderungen | Geomechanics and Tunnelling | 4/2018 | 366-373 | Topics |
AbstractThe use of Building Information Modelling (BIM) for tunnelling projects, is not yet very common in Austria or Germany. First attempts to use BIM in tunnelling are being undertaken on specially selected and supported projects, but this can only be considered a first small step. In the following article, the current status and progress of BIM in tunnelling in Austria and Germany will be described and compared. Furthermore, the article focuses on a range of different aspects of BIM in tunnelling. Particular attention is paid to the special requirements of underground mining. This regards the challenges of the state of the art software capacities concerning the complex geometrical structures of underground constructions. Another important aspect is the interaction between ground and excavation method. The physical properties of the ground will never be completely known. Therefore, consolidated basics/rules for the behaviour and treatment of the ground have to be developed. BIM follows the principle of “first build virtually, then in reality”, for which reason construction companies have to be involved in the early planning phase. It is necessary to develop new contract models and to strive for a cooperative partnership. x | |||||
de Oliveira, Daniela Garroux G.; Thewes, Markus; Diederichs, Mark S.; Langmaack, Lars | EPB tunnelling through clay-sand mixed soils: Proposed methodology for clogging evaluation | Geomechanics and Tunnelling | 4/2018 | 375-387 | Topics |
AbstractThe clogging of Tunnel Boring Machine (TBM) tools by soils has long been investigated, owing to the numerous difficulties arising in shield tunnelling as a result. Its occurrence leads to operation delays owing to the frequent and lengthy interventions required to unblock the soil stuck to the excavation tools and screw conveyor. Several authors have proposed laboratory tests for evaluating the clogging potential, however, those include limitations, such as not considering the clay fraction in a soil. One of these methods is the empirical stickiness evaluation, whereby a mixer and a beater are used to define a clogging evaluation parameter. Following an extended test campaign using soils with different clay contents and minerals, it became clear that this method was not adequate to provide reliable information regarding the tendency of a soil to clog in a tunnel drive. A new device was then implemented, which adds to the first method a kinetic energy impulse via dropping of the beater from a certain height. This combination of methods could provide a reasonable approximation of the potential for clogging to occur along Earth Pressure Balance Machine (EPB) tunnel drives. This paper presents the results of the proposed combined methodology for clogging evaluation, as well as the research evolution that led to the addition of the beater dropping stage. x | |||||
Schubert, Wulf | 25 years of research and development at the Institute of Rock Mechanics and Tunnelling at Graz University of Technology / 25 Jahre Forschung und Entwicklung am Institut für Felsmechanik und Tunnelbau an der Technischen Universität Graz | Geomechanics and Tunnelling | 3/2018 | 203-212 | Topics |
AbstractThe Institute of Rock Mechanics and Tunnelling at the Graz University of Technology was founded in 1992. From the beginning, the primary focus of research and development was on Alpine tunnelling and slope stability issues, considering geological conditions and their impact on construction. The aim was to improve the current practice, as well as to reduce uncertainties. The research areas can be roughly grouped into rock mass characterization, improvement of monitoring data interpretation, ground behaviour assessment, as well as development and improvement of support elements. The research is documented in about 110 master theses and 30 doctoral theses, and approximately 350 papers. x | |||||
Entfellner, Manuel; Kluckner, Alexander; Lenz, Gerold; Poisel, Alexander; Schubert, Wulf | Short-term prediction of shotcrete utilization based on observations during tunnelling / Kurzzeitprognose der Spritzbetonauslastung auf Basis von Beobachtungen während des Tunnelvortriebs | Geomechanics and Tunnelling | 3/2018 | 214-225 | Topics |
AbstractDisplacement curves in tunnelling depend both on time and the distance from the face and have thus not died down immediately after excavation. Therefore - the applied shotcrete lining experiences temporally variable loading, which depends on the forced strain curve and on the material behaviour of the shotcrete. Overloading of the shotcrete lining leads to crack formation, costly and laborious repair work and possibly also to dangerous situations for those present at the location, and should therefore be prevented. With the method presented in this article, which combines geological-geotechnical parameters and the interpretation of measured displacement data, the accuracy of the short-term prediction of the system behaviour can be improved. This makes it possible to react early to any potential overloading of the planned support and adapt it if necessary (e.g. changeover to ductile support). The article concludes with an explanation of the method through the example of the Semmering Base Tunnel, contract SBT 1.1 - Tunnel Gloggnitz. x | |||||
Pichler, Bernhard; Hellmich, Christian | Hybrid methods for shotcrete and segmental linings tunnel shells - Combining displacement and rotation measurements with computational multiscale mechanics / Hybride Methoden für Spritzbeton- und Tübbingschalen - Kombination von Verschiebungs- und Verdrehungsmessungen mit Mehrskalen-Mechanik | Geomechanics and Tunnelling | 3/2018 | 226-235 | Topics |
AbstractThis contribution highlights recent developments in the analysis and monitoring of tunnel linings based on so-called hybrid methods. In this context, the word “hybrid” refers to a suitable combination of measurement data from geotechnical monitoring, with advanced simulation tools of engineering mechanics. The first part of this contribution refers to the New Austrian Tunneling Method (NATM), where monitoring during construction includes daily measurements of the 3D displacement vectors of “measurement points” installed in “measurement cross-sections”. Shell theory-informed spatial and temporal interpolation of the displacements between the aforementioned “grid points”, allows for reconstructing the evolution of the displacement and strain fields throughout the tunnel shell. Feeding these fields into realistic thermo-chemo-mechanical, potentially multiscale, models for the chemically hardening and creeping shotcrete, allows for the determination of the lining stresses over time. The latter give access to corresponding safety indicators or utilization degrees considering the evolving strength of shotcrete; and they also allow for quantifying the traction forces acting from the rock mass, on the exterior boundary of the tunnel lining. The second part of this contribution refers to the first steps towards the hybrid analysis of segmental lining, as installed in mechanized tunnelling. Relative rotation angles, as measured, in the course of a full-scale test, in the joints between adjacent segments of a segmental ring, are prescribed on a structural mechanics model based on analytical solutions from circular arch theory. x | |||||
Henzinger, Michael R.; Willmes, Michael; Lagger, Manuel; Kathage, Andreas F.; Moritz, Bernd A.; Schubert, Wulf | Detection of voids in the annular gap using ground penetrating radar and determination of the in-situ deformation properties of pea gravel / Detektion von Hohlräumen im Ringspalt mittels Georadar und Ermittlung der in situ Verformungseigenschaften von Perlkies | Geomechanics and Tunnelling | 3/2018 | 236-250 | Topics |
AbstractWhen using shield machines, the excavation support is established using prefabricated concrete segments. The structurally required cavity between the built ring and the rock mass is usually filled with pea gravel in hard rock conditions. The backfilled material ensures the necessary bedding and evenly distributes the rock loads. To evaluate the in-situ deformation behaviour of pea gravel, a testing device was developed that measures the reaction of the backfill under load increase and load decrease on the basis of the static load plate test. The test is carried out via the opening for pea gravel injection. The results have shown that the elasticity of pea gravel is predominantly influenced by the load level and the type of loading. x | |||||
Henzinger, Michael R.; Schachinger, Tobias; Lienhart, Werner; Buchmayer, Fabian; Weilinger, Walter; Stefaner, Raimund; Haberler-Weber, Michaela; Haller, Eva-Maria; Steiner, Michael; Schubert, Wulf | Fibre-optic supported measurement methods for monitoring rock pressure / Faseroptisch unterstützte Messmethoden zur Beobachtung von Gebirgsdruck | Geomechanics and Tunnelling | 3/2018 | 251-263 | Topics |
AbstractLike every civil engineered structure tunnels are subject to an ageing process. The reasons for the degrading of the condition are manifold: not fully completed stress redistribution, deterioration in the rock mass quality through long-term exposure (creeping), weathering or dynamic loads and stresses, to name but a few. All this processes lead to a deformation of the surrounding bedrock and the lining. x | |||||
Galler, Robert; Wenighofer, Robert; Gehwolf, Paul; Stoxreiter, Thomas; Schuller, Erik; Pittino, Gerhard; Darmaev, Enkhe | Overview of current research work at the Chair of Subsurface Engineering at Montanuniversitaet Leoben / Überblick zu laufenden Forschungsvorhaben am Lehrstuhl für Subsurface Engineering an der Montanuniversität Leoben | Geomechanics and Tunnelling | 3/2018 | 265-275 | Topics |
AbstractThe Chair of Subsurface Engineering at the Montanuniversitaet Leoben is part of the Department of Mineral Resources Engineering. Regarding research and development, the chair cooperates with several departments of the university, such as the Departments of Petroleum Engineering, Environmental and Energy Technology, Product Engineering and Polymer Engineering. In addition to the construction of the ZAB, a research and development but also training and education centre at the Styrian Erzberg, some other research projects at the chair have recently been reported in this journal. These include, for example, research on segmental lining design in collaboration with with the ÖBB-Infrastruktur AG, and also topics such as disc force and face monitoring systems for TBMs. This research is deliberately not discussed here; rather research is reported that has received less attention lately. This includes further developments mainly relating to laboratory tests, the research field of rockfall simulations, international research cooperations, and also work on BIM implementation at the ZAB-Zentrum am Berg. x |