Artikeldatenbank
Autor(en) | Titel | Zeitschrift | Ausgabe | Seite | Rubrik |
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Schütz, Holger; Konietzky, Heinz | Studies of flooding induced by seismicity in the Schlema-Alberoda uranium mine / Untersuchungen zur flutungsinduzierten Seismizität im Uranerzbergwerk Schlema-Alberoda | Geomechanics and Tunnelling | 5/2016 | 508-514 | Topics |
KurzfassungThe uranium mine in Schlema-Alberoda near the town Aue in south-east Germany was operated between 1947 and 1990. In 1979, a seismic event with local magnitude of ML = 2.9 and intensity MSK = 5 (Medvedev-Sponheuer-Karnik scale) was monitored close to the mining area. Due to this event and observations of underground dynamic de-stressing, a local seismic network was installed and extended in the following years. Seismic events were routinely located and source parameters for selected events were determined [1], [2]. It was found that most of the sources of dynamic events are located outside the mine, in the neighbouring granitic intrusion. During the period of active mining, continuous online evaluation of seismic events was performed in conjunction with online hazard evaluation [2]. x | |||||
Gaul, Felix; Eggenreich, Stefan | Installation of a microseismic monitoring system in the Mittersill scheelite mine / Aufbau eines mikroseismischen Ãœberwachungssystems im Mittersiller Scheelit Bergbau | Geomechanics and Tunnelling | 5/2016 | 515-523 | Topics |
KurzfassungThe 500.000 t/a underground Mittersill scheelite mine produced around 12 Mio. t during its 40 year lifetime. The active western field dips with 55° to the NNW under the western flank of the steep valley. The ore zone is developed over a vertical length of 600 m from its outcrop at 1.250 m down to the 650 m asl. The deepest workings are already more than 1.000 m below surface due to the dipping below the mountain range. Open stoping with backfill, cut and fill as well as sublevel caving are the prominent mining methods. End of 2015 a micro seismic system from Canadian ESG Solution was installed to get a better understanding of induced stresses and movements in rock formation. As of December 2015 the system consisting of ten sensors are constantly recording all microseismic events in the mine at a depth between 500 and 1.000 m. The events are analysed and graphically displayed according their location, magnitude and category. x | |||||
Wagner, Horst; Ladinig, Tobias; Blaha, Hannes | Design considerations for pillar systems in deep mines | Geomechanics and Tunnelling | 5/2016 | 524-528 | Topics |
KurzfassungPillar systems in mines are statically indeterminate systems. The paper presents the results of numerical investigations to evaluate the effects of panel dimensions on pillar loads. It is shown that pillar load in deep mines is strongly influenced by the lateral and vertical extent of extraction panels. The commonly applied tributary area concept does not account for these effects and is an oversimplification that has to be applied with caution. The effects of local pillar failures on stability of pillar workings are examined using simple models. It is shown that limiting panel dimensions by substantial barrier pillars can reduce the danger of regional pillar collapses and enhance overall mine stability. x | |||||
Gomes, Alexandre R.A.; Rojas, Eduardo; Ulloa, Juan Carlos | Severe rock mass damage of undercut and extraction level pillars at El Teniente Mine | Geomechanics and Tunnelling | 5/2016 | 529-533 | Topics |
KurzfassungThe El Teniente Mine of Codelco is one of the largest underground mine operations in the world. The mine employs massive mechanised panel caving methods with pre-undercut variants to extract copper-molybdenum ore, producing 140,000 t/d, mainly of primary copper ore. In the context of a study of rehabilitation measures for collapsed zones at the Esmeralda mine, which is one of Tenientés most important operations, a preliminary assessment of the post-collapse pillar's rock mass condition was carried out, allowing the characterization of the damage zone surrounding the drifts and some insights into the likely pillar's rock mass damage development. The paper outlines these findings and discusses some underlying factors that may also have influenced the process. x | |||||
Klitzen, Jens; Herdina, Johann | Hydroshield drive with a diameter of 13 m in the Lower Inn Valley - Project design and experience from construction of contract H3-4 / Hydroschildvortrieb mit 13 m Durchmesser im Unterinntal - Projektplanung und Erfahrungen im Baulos H3-4 | Geomechanics and Tunnelling | 5/2016 | 534-546 | Topics |
KurzfassungIn the Lower Inn Valley of the Tyrol, Autria, the existing railway line has been upgraded. In the course of these works a two-track tunnel with an excavated diameter of 13.03 m was built in the track section H3-4 Münster/Wiesing. The tunnel was excavated with a slurry TBM. Demanding geotechnical conditions on this difficult contract necessitated changes to the overall concept. After tendering and the award of contract, the client and the contractor started the construction phase with different expectations. We report on the strongly differing experiences of the parties during the construction of the works. At the end, we draw conclusions for both parties from the experience gained during the successful completion of the project. x | |||||
Daller, Josef; Diewald, Martin; Lemmerer, Johann; Zwittnig, Gerald | Expectations and reality of the mechanised tunnel drives for the Wienerwald Tunnel / Erwartung und Wirklichkeit der TBM-Vortriebe am Wienerwaldtunnel | Geomechanics and Tunnelling | 5/2016 | 547-555 | Topics |
KurzfassungThe 13.35 km long Wienerwald (Vienna Woods) Tunnel forms a key element of the new railway line between Vienna and St. Pölten. The 11 km long twin-tube western section of the tunnel was constructed using two tunnel boring machines, type TBM-S, with an excavation diameter of approximately 10.7 m, and a water pressure-relieved, double shell lining system. A Swiss unsealed, stacked segment lining system was used. In the year 2000, a TBM with these dimensions represented new territory for ÖBB-Infrastructure AG, so intensive investigations of the technology were undertaken from the feasibility study and permit application phases onwards. Risk analyses in respect of geotechnical engineering, TBM design and segmental tunnel lining, cross-checking of the construction schedule and costs that were estimated during the tender phases were undertaken. Together with a comprehensive and thorough investigation, this led the client to the conclusion that the tunnelling work in the western section should be tendered with two alternatives (conventional tunnelling and TBM drive). Appropriate tender evaluation criteria allowed an objective comparison of the submitted tenders to be made and resulted in an unproblematic contract with the western section being awarded for the TBM system. The expectations of the client and the contractor with regard to geology and geotechnics, construction schedule and construction process are described. Deviations from these expectations and the actual technical and construction difficulties encountered are explained, along with the corresponding solutions that were used to overcome these problems. x | |||||
Jesel, Thomas; Amberg, Felix; Rohrer, Thomas | TBM drives at the Gotthard Base Tunnel - Design and experience from tunnelling in Faido / TBM-Vortriebe am Gotthard Basistunnel - Projektierung und Erfahrung aus dem Vortrieb Faido | Geomechanics and Tunnelling | 5/2016 | 556-568 | Topics |
KurzfassungIn the course of designing the Gotthard Base Tunnel, extensive questions were considered about the tunnelling conditions to be expected and the resulting requirements for the TBM. Naturally this mainly concentrated on the achievable advance rates and the associated costs. The tunnelling works have now been completed and the essential assumptions and decisions from the design phase could be confirmed. Experience does however also show that the behaviour of the rock mass could not always be correctly predicted in its entireness and a corresponding flexibility in the use of support measures is unavoidable, which is only possible with suitable tunnelling equipment and machinery. The present article collects the essential data and facts from the TBM drives and described the areas where significant deviations arose. Particular attention is paid to the following subjects and the corresponding effects: wear to the cutterhead, heavy water ingress, rockburst, reciprocal influencing of the two tunnel drives under poor geological conditions and the collapse in the Tenelin Zone. The stated matters are described with a comparison against the assumptions made in the design phase and a complemented with few of the lessons learnt. x | |||||
Köhler, Hans; Rengshausen, Rainer | Metro Doha Green Line - EPB TBM tunnelling under very special circumstances / Metro Doha Green Line - EPB-Vortriebe unter Berücksichtigung sehr spezieller Randbedingungen | Geomechanics and Tunnelling | 5/2016 | 569-579 | Topics |
KurzfassungAs part of the Qatar National Vision 2030, the capital of Qatar - Doha - is being expanded into a modern centre for economy, trade and sport. A main part of this plan is the establishment of an efficient infrastructure with modern means of transportation. x | |||||
Benedikt, Johannes; Lemmerer, Johann; Köpf, Manfred; Obermeier, Oskar | Excavation of the Perschling Tunnels by TBM - expectations and reality - lessons learned / TBM-Vortrieb Tunnelkette Perschling - Erwartung und Wirklichkeit - Erfahrungen und Erkenntnisse | Geomechanics and Tunnelling | 5/2016 | 580-594 | Topics |
KurzfassungIn the course of constructing the new Vienna - St. Pölten high-speed railway line, three TBM tunnels with an excavated diameter of approx. 13 m were driven between 2005 and 2010. The total length of these three tunnels including portal structures, cut-and-cover and top-down sections was approx. 7.4 km, of which 6.2 km were excavated by TBM-S. The tunnels were constructed with drainage systems and two-pass linings in the tunnel arch. During the feasibility study, the permit application design and the tender design phase, detailed risk analyses were performed for excavation method (TBM or NATM), machine type (TBM-S or SM-EPB) and lining type (single- or two-pass). The expectations of the client during the design phase and those of the contractor during the bidding phase are compared and discussed, taking into account construction time considerations, geotechnical risk assessments, lining design, machine type and construction sequence as well as the allocation of risks between client and contractor. The reality of the project, i.e. the construction time actually needed, the challenges encountered, the problems solved and the joint approach adopted to implement the project as well as the lessons learned (experiences and findings) are all described. x | |||||
Arioglu, Basar; Gokce, Hasan Burak; Malcioglu, Fatma Sevil; Arioglu, Ergin | TBM Tunnel under the Bosphorus for the Istanbul Strait Road Crossing Project | Geomechanics and Tunnelling | 4/2016 | 303-309 | Topics |
KurzfassungThe population increase in Istanbul is also reflected in car ownership, which brings an extensive traffic load to the city, especially to the two bridges over the Bosphorus. After feasibility studies, a double deck, 3.4 km subsea tunnel with a 13.7 m diameter at a maximum depth of 106 m below sea level and a capacity of 100,000 cars/day was initiated as a solution for the city. The tunnel, excavated by a custom-made mixshield slurry TBM, passes through very complex geological structures including the Trakya formation, transition zones and marine sediments in a highly seismic area. x | |||||
Gokce, Hasan Burak; Demir, Korhan; Bakir, Ayd?n; Aribilginc, Tamer; Arioglu, Ergin | Asia Transition Box and Conventionally Excavated Twin Tunnels for the Istanbul Strait Road Crossing Project | Geomechanics and Tunnelling | 4/2016 | 310-316 | Topics |
KurzfassungThe 14.6 km long Istanbul Strait Road Crossing Project is a safe, quick and environmentally responsible alternative road link between Asia and Europe, as such it is being constructed under a Build-Operate-Transfer contract by a public-private partnership. The investor/contractor has committed to build the Project in 55 months and to operate the facility for a concession period of approximately 25 years. This article examines the project's two critical structures located in the Asian side of Istanbul, considering site investigation, construction and monitoring. The first structure is a cut and cover construction next to the Bosphorus, called the Asia Transition Box (ATB), which enabled the launching of the TBM and conventional tunnels. The second is the conventionally excavated twin tunnels (CETT), which pass under a highly urbanized part of Istanbul and provide the transition from the highway into the tunnel under the Bosphorus. x | |||||
Özcan, Baris; Duman, Emre; Türkoglu, Aykut; Kayali, Sanem; Saenz, Ignacio | Design and construction of the mined Kisikli Station on the Üsküdar-Çekmeköy Metro Line Project | Geomechanics and Tunnelling | 4/2016 | 317-325 | Topics |
KurzfassungThe Üsküdar-Çekmeköy Metro Line (UCM), which is located on the Asian side of Istanbul, is an 18 km underground metro line with 27 km of TBM tunnel, 13 km of NATM tunnel and 16 stations. Apart from being a completely tunnelled station, it has several other features. It is the deepest station in this metro line with the platform depth 45 m below surface level. The station is being built in a complex geology that contains several passive fault zones. The ticket hall and technical rooms are also located in an NATM tunnel with an excavated width of 20 m. Most of the passenger circulation is planned to be carried out by elevators. x | |||||
Tokgöz, Nuray | An assessment method for fine-grained sedimentary materials excavated by EPB TBM | Geomechanics and Tunnelling | 4/2016 | 326-337 | Topics |
KurzfassungThe aims of this study are to find a solution for the problems (lumping, adhesion, and clogging) encountered with fine-grained sedimentary materials, minimize the time and cost of excavation, and decrease the potential environmental effects due to soil conditioning chemicals used in the process of excavating a waste water tunnel. Therefore, this study will contribute important technical knowledge regarding design and implementation of excavation with TBM to the mining and construction industries as well as for optimization in mechanical engineering. x | |||||
Kohlböck, Bernhard; Koc, Onur; Ayten, Türkay | Istanbul Strait Road Tube Crossing: Design of NATM Tunnels and Asian Transition Box Excavation | Geomechanics and Tunnelling | 4/2016 | 338-344 | Topics |
KurzfassungIstanbul is among the fastest growing megacities in the world and the only one located on two continents, divided by the Bosphorus strait. The geographic situation together with the enormous growth of population impose great challenges, especially considering urban and infrastructure development. The Bosphorus Strait Road tunnel, also called Eurasia Tunnel, is the first road tunnel connecting the European and the Asian side of the city with the aim of alleviating Istanbul's traffic pressure and reducing the travel time between Kazlıçeme and Göztepe from 100 to 15 minutes. This article focuses on the design of the twin tunnels and the transition box from NATM to TBM on the Asian side. x | |||||
Shalabi, Faisal I.; Cording, Edward J.; Paul, Stanley L. | Sealant behavior of gasketed segmental tunnel lining - Conceptual model | Geomechanics and Tunnelling | 4/2016 | 345-355 | Topics |
KurzfassungGasket sealant behavior along joints of concrete tunnel lining depends on gasket-gasket and gasket-groove contact loads, bonding between gasket and groove, and gasket lateral extrusion. As the gaskets are made of polymers, gasket contact loads are expected to drop with time due to relaxation. Reduction in the contact load with time is expected to affect the gasket sealant capacity. Gasket-gasket contact loads depend on many factors such as: stiffness of the gasket material, gasket shape and volume, groove size and configuration, gasket base configuration, and the amount of gasket compression. In this work, the mechanical and sealant behavior of gaskets in grooves were investigated. Two types of gaskets were considered: open base gasket for low design water pressure (less than 600 kPa), and closed base gasket for high water pressure (up to 4###, 000 kPa). The work focused on gasket-in-groove load deformation behavior and gasket sealant potential including the effect of gasket contact loads, relaxation, extrusion, and the change in joint gap during water pressurization. The effect of gasket base conditions (fingers base vs. closed base) on the gasket sealant behavior was also considered in this work. A conceptual model was developed that explains the leakage of the gasket as water pressure is applied. x | |||||
Paternesi, Alessandra; Schweiger, Helmut F.; Schubert, Peter | Verification of a rheological constitutive model for shotcrete through back-analysis | Geomechanics and Tunnelling | 4/2016 | 356-361 | Topics |
KurzfassungTunnel excavation represents a particularly challenging problem from the design point of view, mainly due to the uncertainties characterising the soil or rock mass behaviour and to the difficulties in the prediction of the stress state on the structural supports. This explains why tunnel designers mostly rely on observational data, adapting excavation sequences and support measures during the construction phase (at least in the case of traditionally excavated tunnels), especially for deep tunnels, where the geological and geotechnical uncertainties can be significant. However, the observational method requires a reliable monitoring system as well as considerable work to interpret and back-analyse data measured during construction. On the other hand, this interpretation and back-analysis represent an important step in gaining better understanding of the system response and allowing improvement of the design, thus avoiding excessively conservative and uneconomical solutions. In this paper, a back-analysis of stress and displacement measurements is presented for a NATM tunnel excavation in rock, carried out using a rheological model for shotcrete. It is shown, consistently with the previous literature on the topic, that the use of an advanced model improves the prediction of tunnel behaviour compared to the common practice of using quasi-elastic E-moduli. x | |||||
Gehwolf, Paul; Monsberger, Christoph; Barwart, Stefan; Wenighofer, Robert; Galler, Robert; Lienhart, Werner; Haberler-Weber, Michaela; Moritz, Bernd; Barwart, Christian; Lange, Andreas | Deformation measurements of tunnel segments at a newly developed test rig / Deformationsmessungen an Tübbingen mit einem neu entwickelten Prüfstand | Geomechanics and Tunnelling | 3/2016 | 180-187 | Topics |
KurzfassungWith the use of tunnel boring machines under different geological and geotechnical conditions, the support with precast elements has been state of the art for decades. For the verification of the load-bearing and deformation behaviour of these high-strength reinforced concrete elements under exact known loading conditions, a test rig has been developed and implemented in a cooperation between experts of Austrian Federal Railways (ÖBB-Infrastruktur AG, SAE Fachbereich Bautechnik/Tunnelbau) and the Montanuniverität Leoben (Chair of Subsurface Engineering). The newly developed segment test rig allows biaxial tests on real segments. Due to the modular construction it is feasible to test segments with different geometries and dimensions. The obtained findings should be included in the optimization of these elements. Furthermore, the optimisation of the reinforcement design and replacement of steel bar reinforcement with fibre reinforcement is being investigated. With this test rig, an important step has been taken towards new technologies and materials in the field of segment linings. Currently, tests with distributed fibre optic sensing systems are carried out in cooperation with the Graz University of Technology (Institute of Engineering Geodesy and Measurement Systems - IGMS). A fibre optic sensing cable can be embedded in the segment during production and used for lifelong in-situ deformation measurements of the segment. x | |||||
Henzinger, Michael R.; Radoncic, Nedim; Moritz, Bernd A.; Schubert, Wulf | Backfill of segmental lining - State of the art, redistribution behaviour of pea gravel, possible improvements / Tübbingbettung - Stand der Technik, Umlagerungsverhalten von Perlkies, Verbesserungspotenzial | Geomechanics and Tunnelling | 3/2016 | 188-199 | Topics |
KurzfassungWith mechanized shield tunnelling the quality of the backfill is of significant importance for the stability of the lining. The used material affects the interaction between support and rock mass. Therefore, the choice of a proper backfilling material is of great importance for the system behaviour. Scaled model tests have been carried out investigating the relocation behaviour of pea gravel within the annular gap. The tests have shown that especially with Double shielded TBMs a distinct relocation mechanism is triggered by the regripping process. This leads to an unfavourable bedding situation immediately behind the TBM shield. x | |||||
Wilfing, Lisa; Käsling, Heiko; Goliasch, Robert; Moritz, Bernd; Thuro, Kurosch | Penetration tests at the Koralm Tunnel (KAT2) - The right tool to improve penetration prediction in TBM tunneling? / Penetrationsversuche am Beispiel des Koralmtunnels (KAT2) - Ein Werkzeug zur Verbesserung von Penetrationsprognosen im maschinellen Tunnelbau? | Geomechanics and Tunnelling | 3/2016 | 200-209 | Topics |
KurzfassungPerformance prediction is one of the crucial issues for estimating excavation costs and construction time of tunnel projects. In mechanized tunneling, TBM performance highly depends on achieved penetration rate and cutter wear. The aim of the research group ABROCK and the topic of this paper is the improvement of penetration prediction by performing on-site penetration tests. Therefore estimated parameters by two existing prediction models (Gehring model, Colorado School of Mines model) are compared with the results of penetration tests at Austrians large infrastructure project of the OeBB Koralm tunnel construction lot KAT2. Penetration tests are a common tool to determine the performance of a TBM in certain geological environments. During a test, the TBM is operated under defined conditions that allow the comparison of different tunnel projects and machine types in analogous geological conditions. Results show that only for a narrow scope, considered prediction models reveal appropriate fitting. Once the rock mass is fractured or the stress level within the rock mass changes, existing models are not applicable. This fact emphasizes the need of an update for penetration prediction models by implementing a correction factor for discontinuities and the stress state in a rock mass. This may result in a new prognosis model called Alpine model. x | |||||
Gaich, Andreas; Pötsch, Markus | 3D images for digital tunnel face documentation at TBM headings - Application at Koralmtunnel lot KAT2 / 3D-Bilder zur digitalen Ortsbrustdokumentation bei TBM- Vortrieben - Anwendung beim Koralmtunnel Baulos KAT2 | Geomechanics and Tunnelling | 3/2016 | 210-221 | Topics |
KurzfassungWithin the scope of a research activity of ÖBB-Infrastruktur AG (Austrian Federal Railways) improvements for tunnel face documentation during TBM tunnelling are investigated. This contribution presents an autonomous imaging unit for taking videos of the tunnel face. The unit is installed during maintenance shift in the cutter head of a hard rock TBM. While turning the cutter head, a video is taken. Simultaneously a smartphone that also controls the camera tracks the orientation of the imaging system. From the video a consistent three-dimensional image is generated using latest algorithms from photogrammetry. The resulting 3D images are used for determining single block detachments from the tunnel face as well as quantifying the planarity in general. They serve for enhancing geological mapping including the determination of discontinuities and provide comprehensive and objective documentation information. First successful applications at Koralmtunnel lot KAT2 showed the value of this new way of documentation and measurements. x | |||||
Handke, Dieter; Edelhoff, Dennis | Quality and risk management strategy for mechanized tunnelling - From machine concept to process controlling / Qualitätssicherungselemente und Risikomanagementstrategie für den maschinellen Tunnelbau - Vom Maschinenkonzept zum Prozesscontrolling | Geomechanics and Tunnelling | 3/2016 | 222-233 | Topics |
KurzfassungMechanized tunnelling is a highly technical construction process, which requires the establishment of precise objectives to consistently guarantee high quality and safety standards while still considering the aspects of time and cost reduction. In the tendering and construction phases, these objectives can be met by the application of a risk management strategy and the integration of quality assurance elements. The implementation of process controlling with the objectives optimization, error prevention and documentation provides a centralized monitoring element in the construction phase. External experts can monitor tunnelling activities in real time and submit recommendations in case of deviations. With downstream analyses, incidents can be evaluated and methodological errors identified. x | |||||
Gehwolf, Paul; Walter, Andreas; Galler, Robert; Wagner, Hanns | Shear tests on flexible shear dowels for use at cross passages with thin segmental linings / Scherversuche von flexiblen Scherdübeln für den Einsatz bei Querschlagsanschlägen mit schlanken Tübbingauskleidungen | Geomechanics and Tunnelling | 3/2016 | 234-242 | Topics |
KurzfassungFor the driving of cross passages in mechanized tunnelling, different systems can be used for load transfer at the cross passage opening. With thin segmental linings, achieving high load-bearing capacity of the precast lining and the load transfer elements used pose a great challenge. For the selection of a system, not only the required support measures but also practical construction aspects such as the integration of the load transfer elements into the precast element and the installation of the elements play an important role. The use of shear dowels as a connection and load transfer element between segment rings in the cross passageoffers new possibilities in mechanized tunnelling. Particularly in connection with thin segmental linings, flexible systems of plastic with integrated steel core make it possible to resist loads with large deformations, both in the radial and longitudinal directions. In order to investigate the system behaviour of the overall system of segmental lining with thin construction and plastic shear dowels, shear tests were performed at the Chair for Subsurface Engineering of the Montanuniversität Leoben with a dowel system as the connecting element between segments. The objective of the research project initiated by the ÖBB-Infrastruktur AG is to determine the effects of different reinforcement concepts on the load-bearing capacity of the connection system. Ways of determining the failure of the construction element based on crack detection are also described. x | |||||
Vigl, Alois; Walter, Andreas; Lemmerer, Johann; Atzl, Georg; Handke, Dieter | TBM research project - Tolerances segmental lining / TVM-Forschungsprojekt - Toleranzen Tübbingausbau | Geomechanics and Tunnelling | 3/2016 | 243-259 | Topics |
KurzfassungIn infrastructure tunnelling projects with shielded TBMs, prefabricated segmental linings are used with various systems and requirements. The required degree of accuracy in segment production and ring assembly is a considerable factor in terms of equipment, time and costs. The required tolerances for segments and ring assembly depend significantly on the segment geometry, lining system and field of application. In order to provide a reasonable basis for allowable segment and installation tolerances, a new approach has been established as part of a research initiative of the ÖBB-Infrastruktur AG with respect to the risks and consequences arising from geometrical tolerances. The paper explains the concept of “tolerance classes” with the approach for their developments, derivation and classification. A practical application example is shown in addition. With respect to the nomenclature of tolerances, a harmonization process has been performed in collaboration with the German committees for underground structures, ZTV-ING and DAUB. The results of harmonizing and proposals of tolerance clarifications are presented within this paper. x | |||||
John, Max; Matousek, Federico; Dallapiazza, Werner | Gotthard Base Tunnel - Comparison of forecast and findings regarding engineering geology and tunnelling / Gotthard-Basistunnel - Vergleich Prognose und Befund aus baugeologischer und tunnelbautechnischer Sicht | Geomechanics and Tunnelling | 3/2016 | 260-275 | Topics |
KurzfassungFor deep tunnels with restricted possibilities for site investigation, deviations from the forecast are usually to be expected. Deviations of geological and hydrogeological conditions have different effects on tunnelling. At the Gotthard Base Tunnel it was found that some areas considered as critical actually behaved most favourably, whereas other areas, such as fault zones and zones of high rock pressure, deviated unfavourably from the forecast with considerable effects on costs and the time schedule. Unfavourable deviations could not be compensated by favourable areas. It should be also noted that these deviations had not been included in risk analyses, because they were unknown, however the original cost prognosis of 1999 provided sufficient financial reserves. These deviations were mastered by intensive probing ahead of excavation and adaptation of design, construction programme and additional measures defined during construction. On the basis of the comparison of forecast and actual conditions, the positive and negative effects of the conditions encountered on tunnelling are described. x | |||||
Vetsch, Hans-Peter; Zbinden, Peter; Märki, Ernst; Ehrbar, Heinz | Gotthard Base Tunnel - Choice of the tunnel system from today's point of view / Gotthard-Basistunnel - Wahl des Tunnelsystems aus heutiger Sicht | Geomechanics and Tunnelling | 2/2016 | 79-93 | Topics |
KurzfassungThe historic rail tunnels in the Alps were consistently built in the form of single-tube twin-track tunnels, starting with the Mont Cenis Tunnel (1871). Only the 19.8 km long Simplon Tunnel at the start of the 20th century was built with two separate single-track tunnels. In 1988, the 53.8 km long Seikan Tunnel became the first tunnel more than 50 km long to go into operation - once more as a twin-track tunnel, although with additional constructional elements such as forced ventilation, emergency stations and a service tunnel. In 1994 followed the Channel Tunnel with a system of two single-track tunnels and a service or safety tunnel as well as a complex ventilation system. For the base tunnels through the Alps, the question arose in Switzerland at the start of the 1990s, what is the optimal tunnel system considering the requirements of construction, safety and operation? A cost-benefit analysis resulted in a system with two single-track tunnels and multi-function stations at the third points as the optimum. Meanwhile, various requirements have been newly formulated so that the question arises whether the same decision would be made with the knowledge available today. x |