Artikeldatenbank
Autor(en) | Titel | Zeitschrift | Ausgabe | Seite | Rubrik |
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Wellmann, Florian; Amann, Florian; Chudalla, Nils; de la Varga, Miguel | Automated geological model updates during TBM operation - An approach based on probabilistic machine learning concepts | Geomechanics and Tunnelling | 5/2022 | 635-641 | Topics |
KurzfassungGeological models are commonly used to predict the position of relevant geological features, such as rock types or faults in the subsurface. These models can contain significant uncertainties, as the geological input parameters are often not perfectly known. Predictions of geological features, for example, on the level of a tunnel during an excavation process, are therefore uncertain. This work shows how these uncertainties can be estimated using probabilistic concepts. Furthermore, an approach is presented to automatically adjust the geological model predictions using measurements of the tunnel boring machine (TBM) operation. To this aim, the geological forward model is combined with a measurement model and both are integrated in a probabilistic machine learning framework. This integration enables a Bayesian inference process using computational methods, enabling an update of the parameters of the geological and measurement models. Based on the inferred parameter distributions, the model predictions on the tunnel level are subsequently updated. The application of the concept in a simple schematic application shows that such a combination can accurately and precisely predict features ahead of the operation within the limits of the model capabilities. In future work, the methods need to be tested with a real case study to evaluate the accuracy of predictions using real-world TBM data and more complex geological models. The framework presented here could directly be extended to this purpose. x | |||||
Filipponi, Marco; Renard, Philippe; Dall'Alba, Valentin; Neven, Alexis | Probabilistic prediction of karst water inflow during construction of underground structures / Probabilistische Prognose von Karstwasserzutritten beim Bau von Untertagebauwerken | Geomechanics and Tunnelling | 5/2022 | 642-649 | Topics |
KurzfassungVarious methods have been developed in recent decades to predict hazards associated with karst voids in underground construction. Common to all these methods is that the predicted range of water inflow is often insufficient for the purpose of implementing the planned construction works. This is usually due to an incomplete knowledge of the karst conduit system within a project area, making it difficult to predict the position and characteristics of karst voids. The method presented in this paper permits a robust prediction of karst water inflow. It is based on a combination of stochastically generated, pseudo-genetic karst conduit systems and hydraulic modelling of the hydrogeological conditions using a Monte Carlo approach. This approach facilitates a plausible estimation of the expected range of karst-induced water inflows and also enables the probability of encountering a karst voids. to be determined. The predictions allow for differentiated treatment of the hazards associated with karst water during the construction and operation phase of underground structures. In concrete terms, this relates to the planning and implementation of exploratory measures and ground-improvement measures, the design of the dewatering system and its monitoring during the construction and operation phase. x | |||||
Morgenroth, Josephine; Unterlaß, Paul J.; Sapronova, Alla; Khan, Usman T.; Perras, Matthew A.; Erharter, Georg H.; Marcher, Thomas | Practical recommendations for machine learning in underground rock engineering - On algorithm development, data balancing, and input variable selection | Geomechanics and Tunnelling | 5/2022 | 650-657 | Topics |
KurzfassungResearch has demonstrated that machine learning algorithms (MLAs) are a powerful addition to the rock engineering toolbox, and yet they remain a largely untapped resource in engineering practice. The reluctance to adopt MLAs as part of standard practice is often attributed to the 'opaque' nature of the algorithms, the complexity in developing them, and the difficulty in determining how the algorithms use the datasets. This article presents tools and processes for developing MLAs, input selection, and data balancing for practical underground rock engineering. MLAs for classification and regression - two main machine learning applications - are presented in terms of developing MLA to extract information from the dataset to obtain the desired output. Engineering verification metrics are selected based on their suitability for specific output. Methods for input selection and data balancing are discussed with a focus on selecting appropriate input data for the problem without introducing bias or excess complexity. Each tool and process for algorithm development, data preparation, and input selection is illustrated with a case study. This article demonstrates that geotechnical practitioners can extract additional value by applying MLAs to rock engineering problems. Once an understanding of the functions of MLAs is reached, the building blocks and open-source code are available to be adapted to suit the rock mass behaviour of interest. x | |||||
Terbuch, Anika; Zöhrer, Alexander; Winter, Vincent; O'Leary, Paul; Khalili-Motlagh-Kasmaei, Negin; Steiner, Gernot | Quality monitoring in vibro ground improvement - A hybrid machine learning approach | Geomechanics and Tunnelling | 5/2022 | 658-664 | Topics |
KurzfassungThis article presents a new approach of quality control to vibro ground improvement techniques based on hybrid machine learning (ML), i.e., a combination of classical analysis and ML techniques. The process is monitored with an instrumented rig equipped with multiple sensors. Key performance indicators (KPIs) are used to identify anomalous foundation columns. As the foundation columns are sub-surface, there is no direct access to ground truth; consequently, unsupervised ML is applied to the recorded time-series data. The risk of not detecting defective elements is reduced by the combination of two independent methods for anomaly detection, KPI- and ML-based classification. The ML is used to gain a deeper process understanding and to detect anomalies which were not considered in the design phase of the KPI. New pre-processing techniques were derived from the insights gained from the ML classifier; this led to a more robust classifier. It is shown how unsupervised ML, using a multi-channel variational autoencoder (VAE) with long short-term memory (LSTM) layers, can be utilized in a knowledge discovery process (KDP). x | |||||
Erharter, Georg H.; Hansen, Tom F. | Towards optimized TBM cutter changing policies with reinforcement learning | Geomechanics and Tunnelling | 5/2022 | 665-670 | Topics |
KurzfassungIn tunnel boring machine (TBM) excavation, cutter maintenance is necessary, but the time for it has to be minimized for efficiency. Although there is extensive literature on TBM cutter wear and predictive maintenance for different industrial applications, there is no optimized policy for cutter changes in TBM tunnelling today. This study aims to investigate the application of reinforcement learning (RL) - a branch of machine learning - for finding optimized policies for cutter changing that maximize the number of working cutters and minimize the maintenance effort. A simulation of a TBM excavation process is developed that focuses on the cutter wear and an agent that controls when cutters must be changed. The simulation uses generated parameters that indicate the cutter life, but the results could be transferred to real sensor data in future excavations once that level of development is reached. The article presents the first results from this RL scenario which can give valuable insights into TBM excavation logistics and presents a challenging multiaction-selection RL problem. x | |||||
Walter, Fabian; Chmiel, Ma?gorzata; Hovius, Niels | Debris flows at Illgraben, Switzerland - From seismic wiggles to machine learning | Geomechanics and Tunnelling | 5/2022 | 671-675 | Topics |
KurzfassungWhere debris flows can impinge on the built environment, early detection of flow events is necessary in order to issue warnings and initiate countermeasures like road or train track closure. In this contribution, previously published work at Illgraben, Switzerland, is compiled, which shows how seismic measurements can be used for debris flow monitoring and warning. The advantage of the seismic approach is that debris flow signals can be detected at large distances eliminating the need for installations within or close to torrents, which are usually difficult to access. It is shown that seismic data contain important information about debris flows, including initiation, propagation, and particle sizes. However, machine learning algorithms, which are tuned with example data rather than physical principles, so far offer the best performance for debris flow detection with continuous real-time data. Such algorithms pave the way for a new class of warning systems, based on data science techniques rather than in-torrent instrumentation. x | |||||
Dietzel, Martin; Eichinger, Stefanie | Scale formation processes - State of knowledge and current challenges / Prozesse der Versinterung - Kenntnisstand und aktuelle Herausforderungen | Geomechanics and Tunnelling | 4/2022 | 347-357 | Topics |
KurzfassungScale formation in water drainage systems occurs in diverse forms. In tunnel drainage systems in particular, calcium carbonate deposition can significantly impair water discharge, resulting in costly maintenance work and tunnel closures. This review paper presents and discusses the state of knowledge as well as the current challenges regarding scale formation in tunnel drainage systems in terms of typification, parameters controlling formation, such as hydrochemistry, interfacial phenomena, microbial activity, and countermeasures, such as appropriate adaptation of construction materials, drainage design, inhibitor use and cleaning. Detailed knowledge of the case-specific scale formation environment and the scaling capacities of the waters provides the basis for the tailored development and evaluation of suitable strategies for successfully reducing maintenance efforts and tunnel closure. For this purpose, time- and site-resolved monitoring of the composition of the solid phases, waters and the tunnel atmosphere during the implementation of the construction project and during the operation of the tunnel is paramount. x | |||||
Koraimann, Günther; Bischof, Karin | Characterisation of microbial biofilms from tunnel drainage water / Charakterisierung von mikrobiellen Biofilmen aus Tunnelwässern | Geomechanics and Tunnelling | 4/2022 | 358-368 | Topics |
KurzfassungMicroorganisms mainly from the domain of bacteria dominate life in the terrestrial subsurface up to a depth of several kilometers. Microbial life in that habitat is dependent on the availability of water and nutrients of biotic or abiotic origin. To produce biomass, bacterial primary producers are capable to use simple building blocks such as CO2, H2, CH4, reduced iron and sulfur, nitrate, phosphate as well as other salts and trace elements. Here, we describe the microbial content of several biofilm samples taken during the construction phase of a railway tunnel between the provinces of Styria and Carinthia (Koralm Tunnel). We could identify bacterial cells using light microscopy and used 16S rDNA based microbial profiling to characterize the bacterial community structure. Our results clearly show that the massive biofilms in tunnel drainage water were produced by a bacterial consortium typical for the deep continental subsurface biosphere. In many cases the majority of the consortium could be assigned to autotrophs, methanotrophs and methylotrophs. x | |||||
Boch, Ronny; Pilgerstorfer, Thomas; Moritz, Bernd | Reduction of scale formation by optimized drainage conditions - Insights from field testing / Reduzierung von Versinterung durch optimierte Drainagebedingungen - Erkenntnisse eines Feldversuchs | Geomechanics and Tunnelling | 4/2022 | 371-391 | Topics |
KurzfassungA field test was carried out in Koralmtunnel in order to enhance process understanding and to optimize the drainage system in a tunnel section that is complex in terms of hydrochemistry, water inflow and mineral (calcareous scale, iron ochre) and biological (microbial mats) deposits. The field test comprised three test fields with different system components and flow characteristics. The development of critical waters and deposits was recorded by continuous measurements of relevant water and air parameters by means of autonomous sensors/data loggers. Furthermore, the components were “forensically” examined with respect to scale formation. The experiments show the crucial importance of gas exchange (CO2, oxygen ingress), filling level (flow geometry/regime), residence time of waters and water-air interaction in the drainage system. The type, material consistency, and amount of scale and biofilms depend significantly on specific gradients. Floating scale crusts formed in stagnant sections, biofilms and iron ochre deposits of soft consistency formed at higher flow rates. Seepage packs and siphons turned out to be potential sediment traps with decreasing flow-through with no access. Drainage hoses and dimpled membranes tend to be beneficial because they can prevent air exchange at relatively high flow rates. High CO2 partial pressure within these components (measured and modeled) inhibits carbonate precipitation. The drainage system is locally designed as a series of direct cross-drains with simple flow paths, restricted air exchange, precautionary cleaning access, and optional water hardness stabilization (liquid conditioning). x | |||||
Pointner, Peter; Sellner, Sabine | Documentation and scale deposits in the Koralm Tunnel - Mapping and sampling in practice / Dokumentation von Versinterungen im Koralmtunnel - Kartierung und Beprobung in der Praxis | Geomechanics and Tunnelling | 4/2022 | 392-401 | Topics |
KurzfassungThe bidding consortium 3G Gruppe Geotechnik Graz ZT GmbH and Pöyry Infra GmbH as well as Geoconsult ZT GmbH and BGG Consult Dr. Peter Waibel ZT-GmbH were awarded the contract for the geological and hydrogeological documentation during the construction of the 33 km long Koralm Tunnel, which was split into three lots. To assess the potential for scale deposition, ongoing documentation and surveys of the groundwater inflows were undertaken in addition to the usual hydrogeological documentation. The scope of documentation included mapping of scale deposition and groundwater inflows, regular site visits and sampling of water and solids in the excavated tunnel (shotcrete and segmental lining) both during and after excavation works. Furthermore, long-term monitoring of the water inflows (on-site parameters, determination of / changes in humidity) and laboratory analysis of the individual and mixed groundwater samples identified the parameters required to assess the potential for scale deposition. The documentation, analysis and assessments provided the basis for ultimately deciding which tunnel sections would require hardness stabilisation measures to reduce or inhibit scaling and calcium carbonate precipitations in the drainage system during the operational phase. x | |||||
Leis, Albrecht; Wagner, Hanns; Eichinger, Stefanie; Domberger, Gunnar; Wedenig, Michael; Dietzel, Martin; Boch, Ronny | Use of green inhibitors for hardness stabilisation of tunnel drainage systems / Anwendung von Grünen Inhibitoren zur Härtestabilisierung in Tunneldrainagen | Geomechanics and Tunnelling | 4/2022 | 402-413 | Topics |
KurzfassungThe drainage system is a core element of tunnel construction and operation. Frequently, natural as well as technical boundary conditions lead to the deposition of scales (especially calcium carbonates) in the drainage system. As a preventive measure - in contrast to post-depositional cleaning procedures - the use of scale inhibitors to treat the drainage water (hardness stabilisation) is an option. ‘Green inhibitors’ are tailored green organic substances that delay or prevent scale formation when added in small concentrations. Moreover, green inhibitors can change the material consistency of scale deposits (soft sinter). An additional advantage of their use is the good environmental compatibility compared to conventional inhibitors. Suitable test procedures can be used to select a substance or product and evaluate or optimise its dosage. The application of polyaspartic acid or polysuccinimide products as ecologically harmless and readily biodegradable agents has proven advantageous in tunnel structures. The choice of liquid or depot stone conditioning essentially depends on the scaling mechanism, in addition to the technical considerations, flow rates and water chemistry. Regarding discharge to existing receiving water bodies, the inhibitor concentration in the water can be measured and controlled by DOC analysis and fluorescence spectroscopy. This article presents contemporary and tunnel-specific case studies. x | |||||
Heissenberger, Roman; Schneider, Martin; Wagner, Hanns; Ferreira, Christina; Schachinger, Tobias | MDR - Effective, flexible and operation-oriented flushing system for railway tunnels / MDB - Leistungsfähiges, flexibles und betriebsorientiertes Drainagespülen in Eisenbahntunneln | Geomechanics and Tunnelling | 4/2022 | 414-423 | Topics |
KurzfassungThe development of a partially remote controlled and automated long distance flushing system used during maintenance is part of the maintenance strategy of the Austrian Federal Railways (ÖBB Infrastruktur AG). The so called MDR (modular drainage flushing system railway) will come into use in the three new railway tunnels Granitztal Tunnel, Koralm Tunnel and Semmering Base Tunnel along the Southern Railway Line. The flushing system consists of the major components MDR flushing box, MDR transport module and various permanently installed components such as flushing shaft, water supply, electricity and data connection. During drainage flushing the MDR is positioned on top of the central flushing shaft in the respective crossway area and connected to the required infrastructure. With the proposed hose length of 600 m, the remote-controlled flushing system flushes all drainages along a length of 500 m in both tunnel tubes as well as the crossways. Once the flushing process and quality check via camera inspection have been completed, the MDR flushing box is moved to the next site at the next crossway during a break in operations. During the flushing process itself, railway traffic does not have to be interrupted. Track closure is only necessary when the MDR is being relocated. In order to increase the MDR flushing box's flexibility the system should also be usable on the tracks themselves. x | |||||
Huymajer, Marco; Operta, Dzan; Mazak-Huemer, Alexandra; Huemer, Christian | The Tunneling Information Management System - A tool for documenting the tunneling process in NATM projects | Geomechanics and Tunnelling | 3/2022 | 259-264 | Topics |
KurzfassungThe documentation of the tunneling process is a crucial task of every tunnel construction project. It provides evidence of the work performed and thus, serves as a basis for invoicing and for several further analyses. Therefore, continuous digitalisation of this documentation is essential. For this purpose, we provide a digital Tunneling Information Management System (TIMS), which is a prototypically implemented software tool for replacing the still common paper-based documentation process of tunneling projects using the New Austrian Tunneling Method (NATM). The data model presented here defines the data structures managed by this tool. Based on this, the software architecture and the implementation of TIMS is shown. x | |||||
Paskaleva, Galina; Niedermoser, Christoph; Vierhauser, Michael; Mazak-Huemer, Alexandra; Hruschka, Sabine; Huemer, Christian | Data Drops for Tunnel Information Modelling | Geomechanics and Tunnelling | 3/2022 | 267-271 | Topics |
KurzfassungIn the Architecture, Engineering and Construction (AEC) industry, as well as in the tunnelling domain, inter-company processes between partners in different roles in large-scale construction projects still exhibit great potential towards digitalisation. Thereby, information should be seamlessly shared between partners according to the Building Information Modelling (BIM) paradigm. Today, different types of artefacts (e.g., models, plans, documents, etc.) are shared at different points in time, which differ in terms of requirements, information content, as well as data formats. In this article, we extend and prototypically implement the concept of Data Drops to provide those artefacts in a digitalised form via a shared Data Drop management platform. For this purpose, we have developed a formal, well-defined indexed data structure on a metadata level. This not only facilitates traceability, but also enables searching for specific meta-information and provides a common view on Data Drops. In addition, a networked view between different drops can be provided. The approach is being evaluated on the use case of a real tunnel construction project. x | |||||
Wenighofer, Robert; Eder, Nina; Speckmoser, Valentin; Villeneuve, Marlene; Winkler, Leopold; Galler, Robert | Adaptive and parameterised 3D BIM model for the tunnel tender and excavation phase | Geomechanics and Tunnelling | 3/2022 | 272-278 | Topics |
KurzfassungBuilding information modelling (BIM) is a frequently discussed topic in tunnelling since it promises less loss of information and reduced lifetime cost of underground infrastructure. There is still some way to go as standardisation in this sector is immature, the implementation of three-dimensional (3D) BIM models is developed for pilot cases of tunnelling only, and data transfer between software tools is a challenge. The long linear structures of tunnels make a specific approach of parameterised and adaptive modelling necessary to meet the requirements of repetitive construction elements and the natural differences of forecast and actual excavation conditions. This approach renders the matching of construction elements in the model and service items feasible for determining quantities for the tender and billing in tunnel projects. In this article, we show that only 57 % of service items can actually be linked to a physical item in traditional two-dimensional (2D) design and highlight the need to consider how to incorporate these items into a BIM model. We also use a case study to propose an approach for parameterised and adaptive modelling of repetitive construction elements and show a way of a continuous data transfer from the forecast tunnelling class distribution via 3D BIM modelling to a billing software without data loss. x | |||||
Winkler, Leopold; Melnyk, Oleksandr; Goger, Gerald | Prerequisites for BIM-based invoicing in NATM projects | Geomechanics and Tunnelling | 3/2022 | 279-283 | Topics |
KurzfassungThe successful management of big tunnelling projects requires the complete documentation of technical and financial data as well as their ongoing evaluation. The current study reviews the possibilities for digital documentation of tunnel construction with the subsequent integration of this data with an invoicing software. It suggests an implementation model, a building information modeling (BIM) project element list and a digital on-site data recording tool for a workflow in New Austrian Tunnelling Method (NATM) projects. This digital resource enables central data management that improves and speeds up automated invoicing processes. x | |||||
Exenberger, Hans; Massimo-Kaiser, Ines Maria; Flora, Matthias | Current developments of digital ground modelling in tunnelling | Geomechanics and Tunnelling | 3/2022 | 284-289 | Topics |
KurzfassungThis article analyses and discusses the current state of the art in the development of digital ground models in tunnelling. Following a review and discussion of the literature research combined with interview responses, a deficit analysis was performed. It shows why current projects mainly work with models and software that function as isolated solutions. A lack of software developments and limited collaborative work mean that the effects of current findings cannot immediately be implemented in models. Accordingly, the enormous potential of full coaction can only be imagined. A further problem is the lack of loss-free data exchange across varying project phases and participants. Science is already moving in the right direction with the goal of harmonising the basic systematics. Finally, requirements for a digital ground model are formulated, and in combination with collaborative working and improved communication, these result in a large number of advanced possible applications. x | |||||
Paar, Gerhard; Mett, Michael; Ortner, Thomas; Kup, Daniel; Kontrus, Heiner | High-resolution real-time multipurpose tunnel surface 3D rendering | Geomechanics and Tunnelling | 3/2022 | 290-297 | Topics |
KurzfassungTunnel surveys making use of photogrammetric three-dimensional (3D) tunnel reconstruction reach resolutions in the millimeter range. Classical big data visualization approaches display point clouds only, neglecting this considerable resolution difference between structure and texture. The article suggests a data structure that separates structural and textural resolution by a regular grid on the unwrapped design surface for 3D, combined with a UV mapping technique as regularly used in computer graphics. For real-time rendering of huge multiscale data sets, the result of photogrammetric commercial-off-the-shelf reconstructions is transformed into a proprietary hierarchical data structure. It facilitates to only load currently relevant parts of the tunnel surface from the hard drive, and only upload and render currently adequate levels-of-detail onto the graphics card for seamless exploration of high-resolution geometric and image 3D tunnel data of arbitrary length. The solution allows for smooth interactive analysis and annotation such as crack identification and mapping, inventory, deformation assessment, and dimensional measurements. Aspects of data generation are addressed and information is given about the data structure, showing examples from entire tunnel 3D representations to demonstrate the smooth behaviour of the real-time rendering of huge data volumes in various scales on standard graphics hardware. x | |||||
Rabensteiner, Stefan; Weichenberger, Franz Peter; Chmelina, Klaus | Automation and digitalisation of the geological documentation in tunnelling | Geomechanics and Tunnelling | 3/2022 | 298-304 | Topics |
KurzfassungIn tunnelling, the geological documentation comprises the daily recording and processing of various data for continuously assessing the geological-geotechnical conditions on-site. One of the core tasks is the documentation of the tunnel face area. With Geodata's Tunnel Mapper, a new measuring system is presented enabling a highly automated data acquisition and the processing of a geo-referenced three-dimensional (3D) tunnel face model. Versions of the measuring system for both conventional and mechanised tunnelling have been developed. From the 3D model, high-quality digital products as well as geometric and geological parameters can be derived, which serve as a basis for decisions on-site. The data can then be integrated into the geological information system TUGIS.NET of Geoconsult, merged there with other data and further (geologically) evaluated, analysed and visualised. A spatial model that has been interpreted and quantified by the geologist can be established and used for target/actual comparisons and forecasts. The model can be transferred into building information modeling (BIM)-compatible data structures for integration into an overall BIM model of the project. The further automation and digitalisation of the geological documentation and the full documentation (geometry and geology) of the face area are achieved in the interaction of the systems mentioned. x | |||||
Hofer, Peter; Eder, Julian; Hager, Lukas; Strauß Bakk, Clemens; Jacobs, Sebastian | RApid Data Integration and Visualization (RADIV) in Subsurface Operations | Geomechanics and Tunnelling | 3/2022 | 305-310 | Topics |
KurzfassungComplex subsurface operations are characterized by a life-threatening environment, a skilled and initiative opponent, and the absence of predictability of the events due to a high level of interdependencies. The reduction of complexity by provision of essential information is crucial for decision-making and rapid integration and visualization of heterogeneous data is essential for successful mission accomplishment. Currently, only standalone applications are available for the underground operational environment, and collaborative planning and working spaces in command and control are missing. The RApid Data Integration and Visualization (RADIV) process addresses exactly this challenge and ensures the lateral continuity of visualization systems across the entire reality-virtuality continuum (2D ó 3D ó mixed reality). It provides a comprehensive command and control system for subterranean operations by processing and visualizing data in different views for different purposes. Integration of these data within the Subsurface Operations Mission Tool (SOMT) will increase the decision quality by improved perception and collaboration. Close cooperation and information exchange between operators and action forces is a prerequisite for success by displaying the relevant information within the truly comprehensive common operational picture, thereby enabling more accurate and precise action reducing own losses and collateral damage. x | |||||
Dorninger, Peter; Studnicka, Nikolaus | Efficient digitization of the Zentrum am Berg research tunnel - From laser scan to triangulated surface model within one day | Geomechanics and Tunnelling | 3/2022 | 311-316 | Topics |
KurzfassungUnthinkable just a few years ago, the precise laser-scanning survey of a kilometer-long tunnel in one day by one operator has become possible. This article describes how 261 scans were taken with a RIEGL VZ-400i laser scanner to digitize the Zentrum am Berg (ZaB) research tunnel with millimeter resolution. The data has been automatically registered during the acquisition process within the instrument. After applying multistation adjustment, a block adjustment postprocess step, the high accuracy of the point cloud with respect to a network of 35 retroreflective bireflex targets has been approved. For further applications such as analysis, simulation, or visualization, a homogeneous 3D-meshed surface model has been created automatically from the point cloud representing an as-built 3D documentation of the tunnel. x | |||||
Konstantis, Spyridon; Prountzopoulos, George; Spyridis, Panagiotis | Ensuring face support and control in soft ground urban tunnels: FEM validation | Geomechanics and Tunnelling | 3/2022 | 317-326 | Topics |
KurzfassungWhen designing and constructing a tunnel in an urban setting with the use of a closed face Tunnel Boring Machine (TBM), the objective is to ensure both the tunnel face stability and the control of induced ground deformations within predefined, acceptable limits. Unless the exerted active face pressure will match the in situ ground stresses, there will be ground deformations taking place in the advance core, i.e., face extrusion and pre-convergence, resulting in settlements or heave for active pressure lower or higher than the in situ stresses, respectively. This article presents the validation through finite element method (FEM) of an analytical methodology that can be applied on soft ground urban tunnels to assess the level of active face support to be considered in numerical analysis, to ensure elastic relaxation in the advance core and thus effective ground deformation control. The methodology combines the classic Anagnostou and Kovari method with the Convergence-Confinement method for face support proposed by Aristaghes and Autuori. In the current article, the methodology is described in detail and subsequently validated through three-dimensional FEM analyses. The article concludes with a discussion on the results and the applicability range of the methodology. x | |||||
Vollmann, Goetz; Stepien, Marcel; Riepe, Werner; König, Markus; Lehan, Anne; Thewes, Markus; Wahl, Hendrik | Use of BIM for the optimized operation of road tunnels: Modelling approach, information requirements, and exemplary implementation | Geomechanics and Tunnelling | 2/2022 | 167-174 | Topics |
KurzfassungIn the operating phase of a road tunnel, not only maintaining or increasing the availability in the network but the economic optimization regarding the life cycle costs of the structure are also important priorities. A consistent application of the Building Information Modelling (BIM) methodology can theoretically make a useful and targeted contribution, as it provides a complete digital model of the structure with all installed elements and the information required for the operator tasks. In the research project FE https://doi.org/15.0623/2016/RRB “Building Information Modeling (BIM) in Tunneling, ” the Institute of Tunneling and Construction Management and the Institute of Computing in Engineering (both Ruhr University Bochum) in cooperation with BUNG Ingenieure AG developed the basics for a BIM-based operating model of road tunnels with funding from the Federal Highway Research Institute commissioned by the Federal Ministry of Transport and Digital Infrastructure. In the article, the results of the research are presented on the basis of specific use cases of a BIM-based operation and maintenance management. x | |||||
Jeon, KiSeok; Dalton, Edward; Bakhshi, Mehdi; Nasri, Verya | Use of BIM technology for optimization and virtual build of TBM tunnels | Geomechanics and Tunnelling | 2/2022 | 175-181 | Topics |
KurzfassungThe practical application of accurate design and coordination in Building Information Modeling (BIM) environment for precast rings in Tunnel Boring Machine (TBM)-bored tunnels is becoming more achievable. These rings, made up of individual segments, are subject to many constraints which include: 1) deviations from theoretical alignment, as modeling the straight centerline of a ring into a curved alignment naturally produces minor deviations in line and grade, 2) avoiding crucifix joints when the joints between segments align in the longitudinal direction, reducing sealing performance, 3) and TBM shield design by minimizing the diameter of the TBM to reduce overcut and required backfill. This article describes the automated procedures for developing our design intent in the BIM environment with consideration for ring length optimization in tunnel curves, geometrical analyses of the staggered pattern of joints, and the minimum diameter and overcut envelope of the TBM shield. This procedure is demonstrated in multiple light-rail transit lines in Montréal including the Réseau Express Métropolitain (REM) airport link tunnel and the expansion of the Montreal Blue Line Metro. Virtual build of these segmentally lined tunnels negotiating all straight and curved drives of the alignment with BIM modeling is realized and summarized in this article. x | |||||
Chiu, Jessica Ka Yi; Hansen, Tom F.; Wetlesen, Thorvald | Norwegian tunnel excavation: Increasing digitalisation in all operations | Geomechanics and Tunnelling | 2/2022 | 182-189 | Topics |
KurzfassungIn the past decades, Norwegian tunnelling has undertaken a major digital development in all operations from planning to the excavation phase. The breakthrough is driven by digital contract requirements from forward-leaning clients and innovative industrial stakeholders, aiming for ever more efficient, quality-oriented and risk-reducing operations. A formal milestone documenting this development was the publication of Digitalisation in Norwegian Tunnelling in 2019. From 2019, most contracts of new infrastructure tunnels must deliver a level 3 Building Information Modeling (BIM) model. Control systems for drilling jumbos are fully digitalised. All drilling must be monitored and documented with Measurement While Drilling techniques. Via cloud servers, the drilling information is interpreted and delivered live to face engineers for decision support. Sensors are used to monitor rock grouting flow and pressure in each drill hole. Digital electronic detonators with exact delay time are used for blasting. Geotechnical mapping is carried out on field tablets. High-resolution scans with RGB imaging must be carried out on the exposed rock surface and after rock support/linings. The next step is to utilise all the collected data to a higher degree by advanced analysis with machine learning (ML) and similar techniques for automation and optimisation. This study reviews and exemplifies the digital focus and achievements in core operations in Norwegian tunnel excavation. x |