Journal articles
Author(s) | Title | Journal | Issue | Page | Category |
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Frenzel, Christian; Galler, Robert; Käsling, Heiko; Villeneuve, Marlène | Penetration tests for TBMs and their practical application / Penetrationstests für Tunnelbohrmaschinen und deren Anwendung in der Praxis | Geomechanics and Tunnelling | 5/2012 | 557-566 | Topics |
AbstractCharacterizing performance of tunnel boring machines (TBM) is important for numerous contractual and technical reasons. A common tool to determine machine performance in the field is the penetration test. The purpose of the penetration test is to operate the TBM for a defined period of time under normalized conditions that allow for interpretation and comparison between tests. The result of a penetration test is a thrust-penetration curve that reflects the excavatability of the rock mass. Prediction models use thrust-penetration curves to calculate the expected performance of a TBM in specific ground conditions. x | |||||
Baumgärtel, Tobias; Fillibeck, Jochen; Vogt, Norbert | Slaking of solid clays and claystones under hydraulic and mechanical action / Zerfall von festen Tonen und Tonsteinen bei hydraulischer und mechanischer Beanspruchung | Geomechanics and Tunnelling | 5/2012 | 567-573 | Topics |
AbstractIn tunnel drives with slurry-supported face in semi-solid to solid clay and claystone, hydraulic and mechanical actions can lead to the slaking of the excavated soil aggregates. Heavy slaking can lead to laborious separation associated with high cost. For investigations as preparation for a project, two test rigs were developed at the Zentrum Geotechnik of the TU München. These can be used to investigate slaking both phenomenologically in series tests and also on a large scale. Investigations on solid clays and claystones showed that varied soil properties influence the slaking. High plasticity indices and high lime contents tend to reduce slaking. Bentonite suspensions can approximately halve slaking compared to water and suitable polymer suspensions can largely prevent slaking. x | |||||
Hollmann, Fritz; Thewes, Markus | Evaluation of the tendency of clogging and separation of fines on shield drives / Bewertung der Neigung zur Verklebungsbildung und zur Feinkornfreisetzung bei Schildvortrieben | Geomechanics and Tunnelling | 5/2012 | 574-580 | Topics |
AbstractShield drives in fine-grained clay soils are often associated with clogging. The tendency of soils to clog depends on numerous parameters. The separation of fines out of the cohesive soil structure also often leads to negative effects. Whether a certain clay soil can become critical depends not only on the soil properties but also the hydrogeological and operating conditions. According to the quantity of water available (groundwater, support fluid), the soil can be altered to a critical consistency range. An evaluation diagram, which takes into account possible changes of water content during the tunnel drive, can be used to evaluate soils under changing conditions (change of available water quantity). x | |||||
Köhler, Manfred; Maidl, Ulrich; Scholz, Marcus; Wendl, Katharina | Geotechnical experience from the hydroshield drives on contracts H 3-4 and H 8 in the Lower Inn Valley / Geotechnische Erkenntnisse aus den Hydroschildvortrieben der Baulose H 3-4 und H 8 im Unterinntal | Geomechanics and Tunnelling | 5/2012 | 581-596 | Topics |
AbstractTwo tunnels were driven in the Lower Inn valley in the years 2007 to 2009 using almost identical mixshields ( 13.03 m) under difficult geotechnical conditions. The tunnelling works were monitored and recorded permanently in real time, from which information can be gained about the system of shield machine and surrounding ground. The documentation of the ground conditions was undertaken by geologists working for the client. The continuous documentation of tunnelling included reporting on the excavated material as the drive was underway and the documentation of face conditions during compressed air interruptions. The combination of recorded machine data and the geological documentation of the tunnel drive provides an extensive data basis, whose evaluation shows the complex relationships of the various tunnelling parameters. x | |||||
Poisel, Rainer; Hofmann, Robert; Mölk, Michael | Investment decisions based on risk assessment / Risikobewertung als Basis für Investitionsentscheidungen | Geomechanics and Tunnelling | 5/2012 | 597-604 | Topics |
AbstractReflecting on the safety of a certain situation can never be answered with a clear “either - or”. This question can only be answered by the evaluation of the occurrence probability of damage, because absolute safety does not exist. x | |||||
Fermaud, Charles; Malioka, Vasiliki | Cost-effectiveness of measures as a basis for safety decisions / Kosten-Wirksamkeit von Maßnahmen als Basis für Sicherheitsentscheidungen | Geomechanics and Tunnelling | 5/2012 | 605-612 | Topics |
AbstractIn absolute terms safety describes a state which is free of any hazard. Indeed, such a state is not achievable - independent of the available technology and the financial resources. To achieve a safe system can only be a conditional objective. Thus the question arises “How safe is safe enough?” The question has been systematically treated for years using quantitative risk analysis and evaluation. Nowadays risk acceptance criteria are often clearly defined. However there is still a large area of discretion, where costs and benefits of additional safety must carefully be weighed. Such balancing is particularly difficult, if the technology to improve safety is available but it is expensive and their effect on safety is potentially small. The presented paper addresses a practicable methodology to evaluate the appropriateness of additional safety measures using cost-effectiveness-criteria. It has been applied in numerous projects related to safety in tunnels. x | |||||
Lauffer-Neumann, Dagmar; Fehleisen, Susanne | Safety on the construction sites of the Koralm Tunnel / Sicherheit auf den Baustellen am Koralmtunnel | Geomechanics and Tunnelling | 5/2012 | 613-620 | Topics |
AbstractSafety in tunnels - during construction and in operation - is a subject that has been brought to attention again and again in recent years - influenced by incidents, media and authorities. Through the example of the major Koralm Tunnel project, it is explained how the requirements, but also the understanding and the implementation of safety on the construction site have changed and developed over the years of project development. Various project phases are described like EIA, design handed in for approval, tendering and construction. The client was, for example, required to produce a detailed safety concept as part of the preparation of tenders and prepare for its implementation during the construction phase. Client and design team thus intrude into areas, which were formerly left to or transferred to the contractor. In the implementation, it turned out that the delineation of responsibility between contractor and client becomes ever more complex and blurred due to this “preliminary work” by the client. The challenge for the future is to increasingly create awareness of the responsibility of the individual in the implementation of the concept and clarification of open questions. This is described through details from the contract Koralm Tunnel 2 (KAT2). x | |||||
Falkner, Leo; Schneider, Johann; Arnold, Josef | Health and safety, prevention and accident costs in construction industry in international comparison / Arbeitsschutz, Prävention und Unfallfolgekosten im Bauwesen im internationalen Vergleich | Geomechanics and Tunnelling | 5/2012 | 621-630 | Topics |
AbstractIf it's not safe, don't do it! Accidents at work and lost days cost a lot of money. A calculation of the consequential cost of accidents by the Allgemeine Unfallversicherungsanstalt (AUVA) estimates this at 19, 128 Euro per accident in 2010. In the construction industry in Great Britain and the USA, employers and employees generally seem to attach more importance to occupational safety and communicate this more effectively than in Austria and Germany. What are the possible explanations for this difference? This article investigates basic cultural differences in general, in the safety culture and different legal traditions. The factors mentioned are not only decisive for the usual contract and cooperation models between employer and employee in these countries but also have an effect on the sickness statistics and the cost of accidents. x | |||||
Zenz, Gerald; Obernhuber, Pius; Czerny, Helmut | The great significance of dam safety in Austria / Der hohe Stellenwert der Talsperrensicherheit in Österreich | Geomechanics and Tunnelling | 5/2012 | 631-637 | Topics |
AbstractEach dam and each reservoir is an individual facility, since their foundation conditions are rarely similar. Due to their location, their height and their storage capacity, dams and reservoirs can hold a considerable hazard potential, which is why they are designed conservatively; projects are examined meticulously (e.g. by the Austrian Commission on Dams) and monitored comprehensively during the construction phase and during operation. To guarantee their continuous safety, dams and reservoirs are monitored with great care by the operating company with the help of trained staff and the latest measuring equipment. The most important measurement data are acquired continuously so as to gain an up-to-date impression of the load-bearing behaviour of the dam and its foundation and to be able to react swiftly and efficiently should any changes occur. x | |||||
Saischek, Michael | The safety equipment of the new line in the Lower Inn Valley / Die sicherheitstechnische Ausrüstung der Neubaustrecke im Unterinntal | Geomechanics and Tunnelling | 5/2012 | 638-643 | Topics |
Abstract100 % safety is never achievable, even with unlimited resources. The basic principles of risk optimisation pose different efficiency. Therefore the risk and the extent of damage can be over-proportionately reduced through very effective implementation of the basic principles. The article describes some measures for the minimisation of risk and their implementation on the Lower Inn Valley project as examples. x | |||||
Thuro, Kurosch; Bundschuh, Moritz | The 2010 rockfall event in Stein an der Traun - causes and triggers / Das Felssturzereignis in Stein an der Traun 2010 - Ursachen und Auslöser | Geomechanics and Tunnelling | 4/2012 | 329-338 | Topics |
AbstractOn January 25th 2010 at about 8 p.m. a block of 432 m3 volume and 1, 026 t weight was released from a conglomerate face, apparently without warning, destroying a family home in the village of Stein on the river Traun. Only two of the four inhabitants could be saved out of the debris. After this event, the question arose whether the rockfall could have been foreseen or if such spontaneous incidents are abrupt and unpredictable. This paper presents the studies conducted to reconstruct the processes leading to the event. The investigations included field mapping, geodetic survey, laser scanning and stereographic photogrammetry of the rupture face, mineralogical analysis of sinter crust thin sections, inventory of the block dimensions and reconstruction of the collapse kinematics, analysis of the weather data prior to the event and a 2D finite element calculation (Phase2) using the geometry of the overhanging conglomerate strata. x | |||||
Plinninger, Ralf J.; Smettan, Klaus; Kresse, John | The 2010 rockfall event in Stein an der Traun - installation of monitoring and early-warning systems / Das Felssturzereignis von Stein an der Traun - Einrichtung von Monitoring- und Frühwarn-Systemen | Geomechanics and Tunnelling | 4/2012 | 339-346 | Topics |
AbstractThe heritage-protected ensemble of Castle Brewery, boarding school and medieval Cave Castle forms the centre of Stein a.d. Traun, Traunstein County, Bavaria/Germany. In large parts of the area, the buildings nestle to or are built directly into a vertical or even overhanging rock slope up to 50 m high, formed of Quaternary conglomerates. Potential rock or block falls as well as larger scale instabilities in this slope represent hazards to the infrastructure below it, as was dramatically shown by the tragic event in January 2010. In order to monitor changes in the rock mass, geotechnical monitoring and early-warning systems were installed in two areas in 2011. This article describes the specific structural and geomechanical situation of the two investigation areas and presents the monitoring concept and the first measured data. x | |||||
Bollinger, Daniel; Gruner, Ueli; Jordan, Peter; Liniger, Markus; Rovina, Hermann | Various methods, different results - on dealing with rockfall modelling in hazard and risk analyses / Verschiedene Verfahren, verschiedene Resultate - Vom Umgang mit Sturzmodellierungen bei Gefahren- und Risikoanalysen | Geomechanics and Tunnelling | 4/2012 | 347-354 | Topics |
AbstractNumerical modelling of rockfall events is an increasingly significant basis for the production of hazard maps and the design of protection structures. The fact that the various programs on the market lead to different results in specific cases has led to discussion. The programs most commonly used in Switzerland are therefore compared with regard to input parameters and results, the main and auxiliary algorithms and further aspects. The difference between deterministic and probabilistic methods is important. The probabilistic method requires great caution and experience, both in the parameter input and in the interpretation of the results. This poses the general question, what uncertainties have to be dealt with in the management of natural hazards. x | |||||
Sausgruber, Johann Thomas; Mölk, Michael; Schreiner, Ivo | Evacuation or protection? Risk analysis as a tool for decision making in the case of a residential building endangered by rockfall / Aussiedlung oder Schutz? Die Risikoanalyse als Entscheidungsgrundlage im Fall eines durch Steinschlag bedrohten Wohnhauses | Geomechanics and Tunnelling | 4/2012 | 355-367 | Topics |
AbstractIn April 2011, a 2 m3 block fell out of a steep rock face in Wipptal, Tyrol, Austria and fell onto a detached house. No one was injured as the house was empty at the time. In a similar event in the 1980s, the garage of a neighbouring house was hit. An initial report found a high danger potential to the house. The house was then evacuated and the inhabitants considered moving out. Regarding the feasibility and possibility of financing protection measures, and as an aid to deciding whether to move out, there is a need for a decision-making basis for the victims and the authorities, and this should be as objective as possible. For this purpose, a risk analysis was carried out including the consideration of engineering-geological, geotechnical and forestry methods. x | |||||
Schober, Andreas; Bannwart, Carsten; Keuschnig, Markus | Rockfall modelling in high alpine terrain - validation and limitations / Steinschlagsimulation in hochalpinem Raum - Validierung und Limitationen | Geomechanics and Tunnelling | 4/2012 | 368-378 | Topics |
AbstractThe Kitzsteinhorn, Salzburg, represents an ideal environment for rockfall simulations in high mountains due to its local infrastructure, the geological conditions and the presence of permafrost. Through climate change and the associated alteration of the glacier and the distribution of permafrost, mass movements increasingly occur in the form of rockfalls and rock slides. In order to improve the understanding and prediction of these gravitational processes, existing models have to be calibrated and adapted or their results have to be verified. As part of the MOREXPERT project, “Monitoring Expert System for Hazardous Rock Walls” (Rockfall 7.1) and 3D (Rockyfor3D 4.1) rockfall simulations were performed. The results of the 3D simulations could be validated directly using orthophotos. It turned out that the modelling results fit very well with the deposits below the investigation area on the glacier and also with the accumulation of debris in the channels and ledges in the face. The largest factor of uncertainty for both programmes is the coverage of snow and ice, respectively the surface of the glacier. As these parameters change with various time scales (hours to years), any simulation of events in the high mountains only represents a snapshot. In order to obtain an overview of the rockfall danger of the entire investigation area, 3D modelling has proved advantageous in addition to the detailed mapping of the terrain. 2D modelling is also useful for a more detailed understanding of rockfall processes in individual zones of the rock face, and its results are ideal for the design of protection measures. x | |||||
Herbst, Martin; Konietzky, Heinz | Numerical modelling of natural rock formations to estimate stability using the example of a sandstone massif in Saxony / Numerische Modellierung natürlicher Felskomplexe zur Abschätzung der Standsicherheit am Beispiel des Wehltumkomplexes in der Sächsischen Schweiz | Geomechanics and Tunnelling | 4/2012 | 379-388 | Topics |
AbstractStatements about stability, weathering behaviour and possible rockfalls affecting a real rock massif were made possible by creating a 3D surface/volume model, using as example the “Großer Wehturm” rock massif, using the high-resolution laser scanning process together with rock mechanical 3D model calculations. The emphasis of this paper is the mathematical modelling, particularly the generation of the 3D model from the surface point cloud and the simulation possibilities. The numerical calculations are based on the Discrete Element Method, considering the rock matrix and joint or bedding interfaces. The 3D modelling delivers, in addition to answers to questions about the extent and degree of deformations and movement mechanisms, knowledge relevant to the transfer of the procedure to other locations. x | |||||
Wendeler, Corinna; Gröner, Eberhard; Matthesius, Jürgen | Protection against debris flows using flexible ring net barriers in the Teufelskadrich, Germany / Murgangschutz Teufelskadrich mit flexiblen Ringnetzbarrieren | Geomechanics and Tunnelling | 4/2012 | 389-396 | Topics |
AbstractThe steep slope along the river Rhine between the German villages of Lorch and Assmannshausen is called the “Teufelskadrich”. The railway line of German federal railways and the motorway run alongside the river Rhine between the foot of the slope and the riverbank. In July 2008, after heavy rain and thunderstorms, several landslides and small debris flows occurred in the area, closing the railway line for several days. Twelve flexible ring net barriers were designed, manufactured and installed within two months as part of an emergency procedure. These lightweight ring net barriers are quick to install and are suitable for slopes with difficult access. They can also blend in with nature once installed, which was important in the “Teufelskadrich” area as the valley is a popular tourist destination. With the new barriers installed on the slope, mobilised landslide or debris flow material is drained and retained by the filtering effect of the ring net barriers. As an additional measure, some of the deposited debris has been stabilised using a slope stabilisation system, utilising high-tensile chain link mesh and soil nails. Most of the future material is thus already retained in the catchment area, further reducing erosion and limiting mass mobilisation in case of an event. x | |||||
Barla, Marco; Barla, Giovanni | Torino subsoil characterization by combining site investigations and numerical modelling / Charakterisierung des Turiner Untergrunds mithilfe von Feldstudien und numerischer Modellierungen | Geomechanics and Tunnelling | 3/2012 | 214-232 | Topics |
AbstractThis paper presents the results of the studies undertaken to assess the geotechnical parameters of the Torino subsoil (Italy). The ground conditions are characterized by a sand and gravel deposit, ranging from medium to highly dense, down to a depth of 8 to 10 m, and cemented soil (in cases a conglomerate), due to calcareous deposition processes, below this depth. The random distribution of cementation in the ground is a key factor in design and construction of underground works. To assess the ground properties as a function of the cementation degree, continuum and discontinuum numerical modelling were used. These were closely linked to the results of the characterization studies carried out so far in the laboratory and in the field (monitored drilling, SPT, large diameter pits, plate loading tests). x | |||||
Barla, Marco; Barla, Giovanni; Gianoglio, Gianluca | Torino Metro Line 1 south extension - modelling and settlement monitoring / Süderweiterung der Turiner Metro Linie 1 - Modellierung und Monitoring der Setzungen | Geomechanics and Tunnelling | 3/2012 | 233-242 | Topics |
AbstractThe excavation of a 3.6 km long tunnel for the Torino Metro Line 1 South Extension was recently completed by a 7.8 m diameter EPB TBM. A critical section of the tunnel was near Corso Spezia, in the Lingotto area, where the main difficulties were the presence of the water table and the poor ground conditions encountered. Another concern was the effect of the excavation on two five-storey masonry buildings adjacent to the tunnel alignment, which were constructed in 1930 and suffered severe damage during World War II. Continuous monitoring was undertaken during excavation as time dependent settlements occurred. 2D Finite Element modelling was used to simulate the excavation and its effects on the buildings. This paper describes the most significant performance monitoring data, which is compared with the results of modelling. x | |||||
Fava, Adriano; Galvanin, Paolo; Socci, Andrea; De Sanctis, Fiorenze; Gamba, Francesco | Design and construction aspects of Milan underground Line 5 - passing over the Bovisa-Dateo railway tunnel / Planungs- und Ausführungsaspekte der Mailänder U-Bahnlinie 5 - Überquerung des Bovisa-Dateo Bahntunnels | Geomechanics and Tunnelling | 3/2012 | 243-260 | Topics |
AbstractThe design and construction aspects related to Line 5 of the Milan Underground are presented with attention to the section of the tunnel passing the city Railway Link between Bovisa and Dateo stations. Numerical modelling was used to design the soil improvement systems around the excavation and under the buildings, and also to establish threshold values of the parameters to be monitored. At the same time, a monitoring system was implemented in order to verify the design predictions during construction and to allow, whenever necessary, the adoption of the corrective actions planned during the design stage. Following a brief description of the work, the fundamental design steps are described in conjunction with the problems that had to be solved, the technical solutions proposed and the approach adopted during construction. x | |||||
Ciufegni, Stefano; Sacchi, Francesco; Utzeri, Luca | Retaining walls, ground improvement works and monitoring for the new high-speed railway station in Bologna / Verbauwände, Bodenverbesserungsmaßnahmen und Monitoring für einen neuen Bahnhof für Hochgeschwindigkeitszüge in Bologna | Geomechanics and Tunnelling | 3/2012 | 261-274 | Topics |
AbstractThe new Bologna high-speed railway station extends approximately 640 m underground, with a width of 56 m and a depth of 25 m. The open-cut excavation work to complete the underground station was designed using an innovative structural system, which entails the construction of reinforced concrete diaphragm walls with unusual shape and structural behaviour. Vaults, diaphragm walls with an arched section, were constructed to absorb the thrust actions. Buttresses, T-section diaphragm walls were designed to absorb actions through flexural behaviour transmitted by the vaults. x | |||||
Rampello, Sebastiano; Callisto, Luigi; Viggiani, Giulia; Soccodato, Fabio M. | Evaluating the effects of tunnelling on historical buildings: the example of a new subway in Rome / Auswertung der Auswirkungen des Tunnelbaus auf historische Gebäude am Beispiel einer neuen U-Bahnlinie in Rom | Geomechanics and Tunnelling | 3/2012 | 275-299 | Topics |
AbstractThe construction of contracts T2 and T3 of the new Line C of the Rome Underground is to be carried out under the historical centre of the city, in an area of great archaeological, historical and artistic value. Significant problems derive from the geotechnical characteristics of the soil, from the presence of buried archaeological remains, and more significantly from the necessity of minimising the effects at the surface on the historical and monumental heritage. This paper illustrates the procedures adopted to evaluate the effects of tunnelling on the existing monuments and historical buildings, with particular reference to contract T2. Specifically, the study of the interaction between construction activities and the built environment was carried out following procedures at two increasing levels of complexity: Level 1 - green-field analyses were carried out first, neglecting the stiffness of the existing buildings for a simplified evaluation of potential damage induced by tunnel excavation; Level 2 - FE computations were then carried out in both two- and three-dimensional conditions, accounting for the stiffness of existing buildings and considering possible long-term effects induced by drainage through the tunnel lining where necessary. The paper illustrates the main aspects of the procedure, using the example case study of Palazzo Grazioli. x | |||||
Russo, Gianpiero; Viggiani, Carlo; Viggiani, G.M.B. | Geotechnical design and construction issues for Lines 1 and 6 of the Naples Underground / Geotechnische Planung und Ausführung der U-Bahnlinien 1 und 6 in Neapel | Geomechanics and Tunnelling | 3/2012 | 300-311 | Topics |
AbstractSince 1839, when the historical railway Naples - Portici was inaugurated, Naples has been characterized by a significant system of urban and suburban railways. The idea of a fully integrated urban rail network dates back to the 1950s, but construction only began in the 1990s. At present, the system includes 54 km of tracks and 69 stations in operation; ten lines with 93 km of track and a further 30 km of new light rail linking 114 stations with 21 interchanges are planned with the completion of the City Transport Plan. x | |||||
Balmer, Olivier | The logistic and construction challenges of an autobahn tunnel with only one accessible portal / Logistische und bautechnische Herausforderungen eines Autobahntunnels mit nur einem zugänglichen Portal | Geomechanics and Tunnelling | 2/2012 | 107-119 | Topics |
AbstractThe Graitery Tunnel is about 2.5 km long and lies on the route of the A16 autobahn through the Jura Mountains. It was originally planned to excavate the tunnel from both portals, but geological problems at the south portal have delayed the drive from that end for years. A new logistic plan was required for inner lining and tunnelling. A mobile bridge construction over 60 m long was used in the tunnel, which made it possible to start the lining works while tunnelling was still underway. Due to newly available geological information, the structural calculations for the south drive and the tunnelling scheme were checked. The latter was thoroughly revised with a change to partial-face excavation in five stages. Although some works will now be completed years later than planned, the tunnel will be handed over to the client for fitting out with not even one and a half years of delay against the original schedule. x | |||||
Schneider, Alex; Tanner, Simon | The Eyholz Tunnel for the Visp southern bypass / Der Tunnel Eyholz der Südumfahrung Visp | Geomechanics and Tunnelling | 2/2012 | 120-134 | Topics |
AbstractThe Visp bypass is an important link on the Swiss national road A9 from Lausanne to Brig-Glis in the Canton of Valais, which is being improved to provide continuous dual carriageway. About 7 km of the alignment of this 8.8 km long section of the A9 will run through tunnels, with the core structures being the 4.2 km Eyholz Tunnel and the 3.2 km Visp Tunnel. Altogether five underground junction structures have to be constructed for the Visp bypass, of which three will be newly excavated and two are enlargements of the existing Vispertal Tunnel. The following report only deals with the Eyholz Tunnel, which has already been largely excavated. Construction of the main contract of the Visp Tunnel is planned to start in 2012. x |