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    <title>Transport Research International Documentation (TRID)</title>
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    <atom:link href="https://trid.trb.org/Record/RSS?s=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" rel="self" type="application/rss+xml" />
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    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
    <docs>http://blogs.law.harvard.edu/tech/rss</docs>
    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
    <image>
      <title>Transport Research International Documentation (TRID)</title>
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      <link>https://trid.trb.org/</link>
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    <item>
      <title>An AI Integrated System for NATM in Tunnel Engineering</title>
      <link>https://trid.trb.org/View/2159549</link>
      <description><![CDATA[It is important to improve the design of the shotcrete-bolting support (NATM) in tunnel engineering. As for this, three kinds of artificial intelligent (AI) techniques, the case-based design, expert system and artificial neural network, are studied to design the support. Because these three methods have their own respective characters, we further put forward a method, called as a divisional weight-adapting multi-expert decision system, to integrate these three methods to take their respective advantages. Thus, the support problem in the design can be optimistically treated. The results for testing this system on real engineering cases show its efficiency.]]></description>
      <pubDate>Sat, 07 Mar 2026 16:05:42 GMT</pubDate>
      <guid>https://trid.trb.org/View/2159549</guid>
    </item>
    <item>
      <title>Numerical Study on Performance of Tunnels Under the Influence of Geometry and Soil Conditions</title>
      <link>https://trid.trb.org/View/2611166</link>
      <description><![CDATA[The current numerical study focused on the assessment of single and twin tunnels through ground settlement, crown and invert level displacements, and structural force variations in non-cohesive and cohesive soils under static loading. Tunnel diameters of 6 m, 9 m, and 12 m were analyzed with a critical spacing of 1.5D. In the case of single tunnels, a 12-m-diameter tunnel induced ~ 210–250% higher displacements than a 6-m-diameter tunnel in both cohesive and cohesionless soil types. For twin tunnels in sand, the displacement was nearly doubled, and hoop forces and bending moments also increased near the second tunnel due to interaction at close spacing. For tunnels constructed in cohesive soil, the variations in hoop force and bending moment were minimal due to the stress-independent nature of clay. This study also compared circular and D-shaped tunnel geometries constructed using Tunnel Boring Machine (TBM) and New Austrian Tunneling Method (NATM), respectively, in cohesive soil. D-shaped twin tunnels showed around 200% higher settlements at ground surface, crown, and invert levels compared to D-shaped single tunnel and circular twin tunnels. Therefore, circular tunnels excavated using TBM performed more effectively, whereas D-shaped NATM tunnels proved highly vulnerable under cohesive ground conditions.]]></description>
      <pubDate>Fri, 21 Nov 2025 08:44:18 GMT</pubDate>
      <guid>https://trid.trb.org/View/2611166</guid>
    </item>
    <item>
      <title>Developing a High-Risk Assessment Model for Tunnel Projects Based on Risk Parameters</title>
      <link>https://trid.trb.org/View/2594072</link>
      <description><![CDATA[New Austrian Tunneling Method tunnel construction projects are highly complex due to geological uncertainties, structural interdependencies, and environmental risks. Traditional risk assessment models primarily evaluate risks based on likelihood and impact, which oversimplifies risk interactions and fails to capture cascading effects. To address this limitation, this study introduces a multidimensional risk identification model that integrates key parameters, including risk conjunction, manageability, frequency, detection, duration, uniqueness, and threat, offering a systematic and comprehensive risk evaluation framework. Validated using real-world data, the model effectively prioritizes the top 20% of high-risk factors, such as tunnel ceiling deformation, groundwater level decline, and side wall deformation, ensuring better risk detection and strategic resource allocation. By applying the Pareto principle, it optimizes mitigation efforts, significantly improving project stability. Compared to traditional methods, this approach enhances accuracy, prioritization, and decision making, making it applicable beyond tunnels to other complex infrastructure projects. Future research should explore machine learning integration for enhanced automation and predictive accuracy, further improving the adaptability of risk assessment frameworks.]]></description>
      <pubDate>Mon, 27 Oct 2025 09:37:13 GMT</pubDate>
      <guid>https://trid.trb.org/View/2594072</guid>
    </item>
    <item>
      <title>Analytical study on seepage field of subsea twin tunnels constructed by NATM</title>
      <link>https://trid.trb.org/View/2024688</link>
      <description><![CDATA[When two tunnels are close to each other, there will be serious mutual interference in the seepage fields. It may result in errors of more than 30% to use an independent single-hole tunnel model for seepage field analysis. An analytical model for the seepage field of subsea twin tunnels is proposed, and an analytical solution of the seepage field is obtained based on the superposition principle. The analytical solution is verified by degradation analysis, a numerical test and an engineering case. It is shown that: (1) The optimal net distance of twin tunnels is 1 times the tunnel diameter. At this time, the water inflow into one of the twin tunnels is the lowest, which is about 70% of the water inflow into the independent single-hole tunnel. (2) When the diameter of the drainage tunnel is reduced by 75% (the excavation area is reduced by 94%, and the project cost is greatly reduced), the water inflow into the main tunnel increases by only 18%. Therefore, small diameter drainage tunnel is the priority strategy. (3) The drainage tunnel should preferably be arranged at 45° obliquely below the main tunnel.]]></description>
      <pubDate>Thu, 22 Sep 2022 09:05:26 GMT</pubDate>
      <guid>https://trid.trb.org/View/2024688</guid>
    </item>
    <item>
      <title>Risk Management for Beijing Subway Tunnel Construction Using the New Austrian Tunneling Method: A Case Study</title>
      <link>https://trid.trb.org/View/1647962</link>
      <description><![CDATA[According to Beijing Subway's extensive expansion plan, the total length of subway lines will reach 1,050 km by 2020, in comparison with 638 km by the end of 2018. The new Austrian tunneling method (NATM) is widely adopted in Beijing subway construction. This paper proposes a fuzzy analytic network process to evaluate the risk for Beijing subway tunnel construction using NATM. Firstly, the risk breakdown structure (RBS)–work breakdown structure (WBS) was introduced for risk identification and 5 major risk factors of the construction projects were identified. Then the model is refined by two-round of Delphi survey and 16 sub-factors are selected. Secondly, the fuzzy analytic network process (FANP) was used to structure the FANP model hierarchically and the weights of the factors and sub-factors of the FANP were calculated. Finally, the refined model is applied to Beijing Subway Line 6 project and a series of risk control measures were taken. The risk control system was shown to be effective and ensure the success of tunnel excavation. This model is believed to serve as a valuable reference for future subway construction in Beijing using NATM in congested urban area.]]></description>
      <pubDate>Thu, 20 Feb 2020 09:30:51 GMT</pubDate>
      <guid>https://trid.trb.org/View/1647962</guid>
    </item>
    <item>
      <title>Vibration mitigation of high-speed railway bridges : application of fluid viscous dampers</title>
      <link>https://trid.trb.org/View/1652295</link>
      <description><![CDATA[At the moment of writing, an expansion of the Swedish railway network has started, by constructions of new lines for high-speed trains. The aim is to create a high-speed connection between the most populous cities in Sweden - Stockholm, Göteborg and Malmö, and the rest of Europe. Thereby, the likelihood of faster, longer and heavier foreign trains crossing the Swedish lines is increased. However, this could be problematic since the dynamic response in railway bridges and, consequently, the risk of resonance increases with increasing train speeds. Bridges are usually designed based on contemporary conditions and future requirements are rarely considered, due to e.g. cost issues. Prospectively, the dynamic performance of existing bridges may become insufficient. Hence, the current expansion of the high-speed railway network results in an increased demand of innovative design solutions for new bridges and cost-efficient upgrading methods for existing lines. The aim of the present thesis is to propose a vibration mitigation strategy suitable for new and existing high-speed railway bridges. The main focus is a retrofit method with fluid viscous dampers installed between the bridge superstructure and the supports, which is intended to reduce the vertical bridge deck acceleration below the European design code limits. Furthermore, the intention is to investigate the efficiency of such a system, as well as to identify and analyse the parameters and uncertainties which could influence its functionality. In order to examine the applicability of the proposed retrofit, case studies, statistical screenings and sensitivity analyses are performed and analysed. Two different models, a single-degree-of-freedom system and a finite element model, are developed and compared. From the different models, it is possible to study the influence from the damper parameters, the variability of the material properties and different modelling aspects on the bridge response.]]></description>
      <pubDate>Tue, 17 Sep 2019 10:32:43 GMT</pubDate>
      <guid>https://trid.trb.org/View/1652295</guid>
    </item>
    <item>
      <title>Innovative Design Modification During Construction of a Twin Tunnel Using Real-Time Field Data</title>
      <link>https://trid.trb.org/View/1632319</link>
      <description><![CDATA[Tunnels are vital substructures that are strongly influenced by the surrounding soil, especially when using the New Austrian Tunneling Method (NATM) in which the soil surrounding the tunnel displaces under part of the applied load and the remaining load is borne by the tunnel initial lining. Displacement monitoring is of great importance in this method and designers should monitor data during construction in addition to a choosing an initial design based on primary soil parameters. The method should be a performance-based approach that is required to meet a target. This paper reports on a case study on an urban twin tunnel constructed using NATM. The construction method is compatible with existing geological conditions and space constraints caused by the high traffic congestion on Valiasr Street in Tehran. The twin tunnel is composed of asymmetric sections and has an overburden of about 12.5 m, height of 8 m and width of 18.3 m with three lanes. In other words, it is composed of a two-lane and a one-lane tunnel with connected initial linings and separate final linings. The numerical modeling was based on a 2D finite element program (PLAXIS version 8). Performance was evaluated by inducing settlement during and after excavation and initial and final stabilization. The model was analyzed statically. During construction, limiting settlement to the regulation values required strategies such as reducing the length of excavation, partial construction of the final lining on one side and reinforcement with micropiles and compensation grouting. The numerical results show that the length of excavation resulted in low efficiency of about 13%, but the micropile elements reduced the resultant surface settlement 30% and the induced total strain 46% over the critical value. In other words, the displacement trend line decreased with a dip of 30%. In comparison with field observations and field data, the numerically estimated settlement at the ground surface was approximately twice that of the measured value and, interestingly, the recorded convergence was fixed during tunneling, suggesting that unknown conditions like a cavity or deep soil with filling material exists above the tunnel. Comparison of the back-analyzed results with the field data showed a decrease in the real values of the geotechnical parameters for the soil layer of more than 20%. This confirms that the existence of local unknown conditions can cause a difference of up to 50% in surface settlement. It was found that the loose soil properties decreased the efficiency of soil improvement to less than 15%.]]></description>
      <pubDate>Mon, 22 Jul 2019 07:58:46 GMT</pubDate>
      <guid>https://trid.trb.org/View/1632319</guid>
    </item>
    <item>
      <title>Conception and Exploration of Using Data as a Service in Tunnel Construction with the NATM</title>
      <link>https://trid.trb.org/View/1530413</link>
      <description><![CDATA[The New Austrian Tunneling Method (NATM) has been widely used in the construction of mountain tunnels, urban metro lines, underground storage tanks, underground power houses, mining roadways, and so on. The variation patterns of advance geological prediction data, stress–strain data of supporting structures, and deformation data of the surrounding rock are vitally important in assessing the rationality and reliability of construction schemes, and provide essential information to ensure the safety and scheduling of tunnel construction. However, as the quantity of these data increases significantly, the uncertainty and discreteness of the mass data make it extremely difficult to produce a reasonable construction scheme; they also reduce the forecast accuracy of accidents and dangerous situations, creating huge challenges in tunnel construction safety. In order to solve this problem, a novel data service system is proposed that uses data-association technology and the NATM, with the support of a big data environment. This system can integrate data resources from distributed monitoring sensors during the construction process, and then identify associations and build relations among data resources under the same construction conditions. These data associations and relations are then stored in a data pool. With the development and supplementation of the data pool, similar relations can then be used under similar conditions, in order to provide data references for construction schematic designs and resource allocation. The proposed data service system also provides valuable guidance for the construction of similar projects.]]></description>
      <pubDate>Wed, 29 Aug 2018 16:13:15 GMT</pubDate>
      <guid>https://trid.trb.org/View/1530413</guid>
    </item>
    <item>
      <title>Safety Factor Assessment of a Tunnel Face Reinforced by Horizontal Dowels</title>
      <link>https://trid.trb.org/View/1465243</link>
      <description><![CDATA[The use of dowels as a reinforcement technique has been successfully applied to improve the tunnel face stability during excavation, for the sake of safety and for the construction speed. The conventional tunneling, e.g. the New Austrian Tunneling Method, promotes the use of such techniques in design for a maximum optimization of the tunnel support. In this work, the kinematic approach in combination with the strength reduction technique is employed to evaluate the safety factor of a reinforced tunnel face. The discretization technique is extended to generate the failure mechanism for a realistic tunnel face shape (non-circular shape). An interaction zone with finite thickness is used to model the interaction between the soils and the dowels. The width of the interaction zone introduces a new parameter in the optimization process. In order to validate the implemented method, the results are compared with those of numerical analysis, which shows that the developed approach is an efficient design tool for the safety factor assessment of a reinforced tunnel face. Several charts are provided for parametric analysis to discuss the influence of the bolt length, the bolt density and the soil shear strength.]]></description>
      <pubDate>Fri, 28 Apr 2017 10:40:11 GMT</pubDate>
      <guid>https://trid.trb.org/View/1465243</guid>
    </item>
    <item>
      <title>Development of an IFC-based Data Schema for the Design Information Representation of the NATM tunnel</title>
      <link>https://trid.trb.org/View/1446288</link>
      <description><![CDATA[A tunnel data schema employing the New Austrian Tunneling Method (NATM) is proposed to efficiently manage and exchange the design information of road tunnels between different computer environments. The data schema was developed by extending the Industry Foundation Classes (IFC) used as standards in Building Information Modeling/Model (BIM) projects. The design guidelines and tunnel drawings were analyzed in order to apply the design information of the NATM road tunnels. From the analysis results, the applicable IFC elements were identified through a comparative analysis with the existing IFC data schema, and new items were defined for the additional necessary elements. The newly defined elements were classified into the parts representing the information of the space occupied by the tunnel and that representing the information on components such as shotcrete, steel ribs, and concrete linings. The applicability of the developed schema was examined by using it to construct an experimental environment, in which information modeling was possible.]]></description>
      <pubDate>Mon, 27 Feb 2017 09:38:43 GMT</pubDate>
      <guid>https://trid.trb.org/View/1446288</guid>
    </item>
    <item>
      <title>Criteria for the Selection of Construction Method at the Ovit Mountain Tunnel (Turkey)</title>
      <link>https://trid.trb.org/View/1446174</link>
      <description><![CDATA[The Ovit Mountain Tunnel (OMT) is a highway tunnel under construction at Mount Ovit between Ikizdere (Rize) and Ispir (Erzurum) in NE Turkey. It will be the country’s longest tunnel about 14700 m long in twin tubes. This paper compares and assesses tunnel excavation by Tunnel Boring Machine (TBM) excavation or drill and blast method for the OMT. Rock mass and material characteristics were evaluated to identify the excavation method. The rock mass classification of the tunnel grounds was performed by utilizing the Rock Mass Rating (RMR), Q system and New Austrian Tunnelling Method (NATM) which was followed by a geotechnical investigation along the tunnel. Twelve boreholes with a total length of 1116.5 m were drilled to assist and verify rock mass classifications. Seventy five rock samples were obtained for mechanical test. TBM method was selected at preliminary design stage of the OMT. But now, the OMT is driven by drill and blast method, using hydraulic excavators and the support is based on the principles of the NATM. The selection of this tunnelling excavation method was decided by morphological site conditions, geological, geotechnical site conditions, time and economic criteria.]]></description>
      <pubDate>Mon, 27 Feb 2017 09:38:13 GMT</pubDate>
      <guid>https://trid.trb.org/View/1446174</guid>
    </item>
    <item>
      <title>Mechanical Behavior Analysis for Parallel Small Spacing Tunnels in a Loess Region</title>
      <link>https://trid.trb.org/View/1417201</link>
      <description><![CDATA[For satisfying the requirements of the normal running and enlarged outer section in the stabling line, a parallel neighborhood metro tunnel with two different inner sections is adopted in the Xi’an Urban Rail Transit Line, one between North Zaoyuan Road and Hancheng Road. Based on the characteristics of the different inner sections and small clear spacing, 2D-FEM was applied to simulate and analyze four construction schemes, of which the shield method was adopted in the left tunnel with a small inner section, and double-heading construction method or cross diaphragm method for the right tunnel with a large inner section. The results show that compared with the construction scheme, the tunnel with a small inner section is excavated first. The larger tunnel, by double-heading construction, is first accomplished and can evidently reduce the disturbance effect on the  surrounding rock and reach a better mechanical state of tunnel lining in order to ensure safety construction.]]></description>
      <pubDate>Mon, 29 Aug 2016 11:14:08 GMT</pubDate>
      <guid>https://trid.trb.org/View/1417201</guid>
    </item>
    <item>
      <title>Finding Best Model to Forecast Construction Duration of Road Tunnels with New Austrian Tunneling Method Using Bayesian Inference: Case Study of Niayesh Highway Tunnel in Iran</title>
      <link>https://trid.trb.org/View/1337995</link>
      <description><![CDATA[Forecasting project final duration (i.e., time at completion) is crucial to project risk management and is always sought by project managers during the construction period. Because of a strong correlation between past and future performances in linear projects, past progress data are the best source of information to forecast final duration of this type of project, including tunneling projects constructed by the new Austrian tunneling method (NATM). Bayesian inference is a robust probabilistic approach that can provide accurate forecasts of final duration based on a project’s past performance. However, results of research in this field have shown that selecting an appropriate model, which represents the unknown pattern of the project’s actual progress well, is the most challenging and subjective part of this approach. Effective risk management necessitates looking for the best model that can forecast project final duration accurately and precisely, especially early in the project. This research was aimed at finding a best progress model for NATM tunneling projects by conducting Bayesian analysis on available data of a massive project, the Niayesh highway tunnel in Iran. The analysis showed that the dual Gompertz function (with flexible lower asymptote) was the most reliable model for this purpose. The results of this research bring advantages to the planning and risk management of NATM tunneling projects, which are discussed in this paper, and can be very useful for future NATM tunnel constructions.]]></description>
      <pubDate>Thu, 26 Feb 2015 10:03:27 GMT</pubDate>
      <guid>https://trid.trb.org/View/1337995</guid>
    </item>
    <item>
      <title>Zum Tragverhalten von Rohrschirmen beim Tunnelbau im Lockergestein</title>
      <link>https://trid.trb.org/View/1322883</link>
      <description><![CDATA[Zur temporaeren Sicherung des ausgebrochenen Abschlags beim Vortrieb von Tunneln im Lockergestein werden haeufig Rohrschirme als vorauseilende Sicherungen eingebaut. Trotz vielfacher Anwendung dieser Methode gibt es bisher fuer die Planung und die Bemessung von Rohrschirmen weder Normen noch Empfehlungen. Diese Luecke versucht der auf einer Dissertation aufbauende Beitrag zu schliessen. Zunaechst wird auf den Stand von Forschung und Technik zu dieser Thematik eingegangen und dazu ueber bisherige Erkenntnisse zum Tragverhalten von Rohrschirmen berichtet. Es schliesst sich die Beschreibung einer Berechnung an einem dreidimensionalen FE-Modell an. Die Rechenschritte im Modell bilden Schritt fuer Schritt die Aushub- und Sicherungsmassnahmen eines realen Tunnelvortriebs ab. Die Berechnung erfolgte fuer den Kalottenvortrieb eines Strassentunnels mit drei aufeinanderfolgenden Rohrschirmen bei Gesamtabschlagslaengen von jeweils 8 Metern. Vor Beginn der numerischen Untersuchungen wurden drei Stoffmodelle zur Beschreibung des Gebirges getestet. Die Vor- und Nachteile dieser Stoffmodelle fuer die Anwendung bei der Berechnung von Rohrschirmen werden vergleichend dargestellt. Zudem erfolgten mit den Stoffmodellen Vergleichsrechnungen am geometrischen FE-Modell. Die Vergleichsrechnungen zeigen, dass das im Rohr entstehende Biegemoment abhaengig vom Stoffmodell ist. Aus den vergleichenden Berechnungen konnte auch abgeleitet werden, dass die Belastungszustaende der Rohrschirme aus wechselnder Be- und Entlastung des umgebenden Gebirges resultieren. Fuer die Hauptuntersuchungen ausgewaehlt wurde schliesslich das Stoffmodell "Hardening Plasticity Soil", das die verschiedenen Steifigkeitseigenschaften bei Be-, Ent- und Wiederbelastungen gut erfasst. Die Hauptuntersuchungen umfassten ueber 100 Variationsrechnungen, bei denen systematisch einzelne Parameter des Modells veraendert wurden. Die variierten Parameter waren: Kalottenquerschnitt, Steifigkeit des Rohrschirms, Ueberdeckungshoehe und Gebirgsparameter. Die Untersuchungsergebnisse zeigen, dass die bemessungsrelevanten Schnittgroessen das Biegemoment und die Normalkraft der Rohre sind. Querkraefte kann man hingegen wegen ihrer geringen Groesse vernachlaessigen. Es konnte gezeigt werden, dass sich die Schnittkraefte waehrend des Vortriebs veraendern. Das am staerksten belastete Rohr bei normalkonsolidierten Boeden liegt bei dem untersuchten Maulprofil in der Naehe der Firste. Bei ueberkonsolidierten Boeden wandert die Stelle der maximalen Biegebeanspruchung in Richtung der Ulmen. Ausserdem werden die Auswirkungen eines Rohrschirms auf die Setzungen und Konvergenzen sowie auf die Stuetzwirkung auf das Gebirge dargestellt. Durch die Anordnung von Schirmen kommt es zu einer Entlastung des Gebirges und zu einer Reduktion der plastischen Zone. Im Bericht werden zusaetzlich zum entwickelten Verfahren einfache Ersatzmodelle auf ihre Eignung zur Abbildung des Tragverhaltens der Schirme untersucht und die Grenzen solcher Verfahren aufgezeigt. Eine Zusammenfassung der Resultate ist unter http://mediatum2.ub.tum.de/node?id=1094674 verfuegbar. ABSTRACT IN ENGLISH: Spilling support consisting of umbrellas made of long pipes or self-drilling hollow-stem injection anchors find increasing application in conventional tunnel drives. Their purpose is to temporarily support the excavation face until the shotcrete is load bearing. This pipe umbrella method has been very efficient on many construction sites. Despite of its frequent application, there are no codes, regulations or recommendations for the design of such support measures. This topic has been investigated within a doctoral thesis. For this purpose finite element method calculations were performed to provide the basis of the derivation of the principles of their load bearing behaviour and to quantify their state of stresses. The following paper provides a brief summary of some results of the above mentioned topic:http://mediatum2.ub.tum.de/node?id=1094674.]]></description>
      <pubDate>Fri, 26 Sep 2014 11:05:56 GMT</pubDate>
      <guid>https://trid.trb.org/View/1322883</guid>
    </item>
    <item>
      <title>Der Bauabschnitt U1/10 der Wiener U-Bahn / Construction section U1/10 of the Vienna Underground</title>
      <link>https://trid.trb.org/View/1317894</link>
      <description><![CDATA[Wie in vielen Grossstaedten wird auch in Wien das U-Bahn-Netz staendig erweitert. Die 1978 in Betrieb genommene, erste Wiener U-Bahn-Linie U1 wird derzeit nach Sueden verlaengert. Die Verlaengerung gliedert sich in verschiedene Bauabschnitte. Es wird ein Ueberblick ueber den Bauabschnitt U1/10 Troststrasse gegeben, der dicht bebautes innerstaedtisches Gebiet unterfaehrt. Die beiden eingleisigen Streckenroehren werden im zyklischen Vortrieb nach der Neuen Oestereichischen Tunnelbaumethode (NOET) mit einer Ueberdeckung zwischen etwa 10 bis 18 Metern aufgefahren. Die Stationen und Schaechte erstellt man in offener Bauweise. Geologisch liegt der Bauabschnitt in miozaenen Sedimenten und quartaeren Ablagerungen oberhalb des freien Grundwasserspiegels. Circa zwei Drittel der Strecke liegen im Loess beziehungsweise Loesslehm mit weicher bis fester Konsistenz. Im restlichen Teil des Bauabschnitts stehen schwach tonige Schluffe mit eingelagertem Grobschluff beziehungsweise schluffigem Sand an. Die Herstellung in offener Bauweise musste wegen Aufrechterhaltung des Strassenbahnverkehrs abschnittsweise erfolgen. Massgeblich bestimmt wurde der Bauablauf in diesem Bereich darueber hinaus durch die Umlegung eines oeffentlichen Hauptkanals, der durch die zu errichtenden Bauwerke verlaeuft. Die Herstellung der Schaechte und Tunnel der Station Troststrasse musste wegen der aufstehenden Bebauung setzungsarm erfolgen. Dies geschah nach Simulationsuntersuchungen verschiedener Varianten mit horizontalen DSV-Schirmen und vertikalen DSV-Saeulen. Diese Sicherungsmassnahmen und die verschiedenen Aushubvorgaenge werden im Einzelnen beschrieben. Der Vortrieb der Streckentunnel erfolgte im Vollausbruch mit mit abgestufter Ortsbrust (Kalotte, Strosse, Sohle), wobei die Abschlagslaenge zwischen 1,30 Meter und 1,0 Meter variierte. Als Voraussicherung verwendete man im Regelfall Spiesse und Ortsbrustanker. Zwischen den beiden Roehren sind in regelmaessigen Abstaenden Querschlaege angeordnet, die in einschaliger Bauweise mit Spritzbeton ausgefuehrt wurden, um Erfahrungen mit der einschaligen Bauweise zu gewinnen. Die Vortriebsarbeiten sollen Mitte 2014 beendet sein und bereichsweise hat die Herstellung der Innenschale schon begonnen. Derzeit liegen die Arbeiten im Terminplan, sodass die Inbetriebnahme des Bauabschnitts wohl wie vorgesehen 2017 erfolgen kann. ABSTRACT IN ENGLISH: As in most of the large European cities, the attractiveness of public transport is also an important matter for the inhabitants of Vienna. For this reason, the Vienna underground railway network has been continuously extended since its inception in 1978. At the moment, the extension of the Line U1 to the south is under construction, with about 50 % running underground and the rest either elevated or at ground level. Construction started in 2012 and the section should open in 2017. Part of this section is contract U1/10 Troststrasse, which runs underground. The tunnels mainly pass through loess and loess-loam soils, and are favourably above the free groundwater table so that only perched groundwater had to be pumped out of wells in the area of the tunnels. The running tunnels are being constructed according to the principles of the New Austrian Tunnelling Method (NATM). The station tunnels for track 2 are also being tunnelled according to the NATM although measures to reduce settlement were essential to comply with the requirement for the permissible tangential inclination of buildings. After various methods had been evaluated, a combination of a horizontal jet grout canopy supported on vertical jet grout columns was chosen. The shafts and the tunnel for track 1 were constructed in cut-and-cover with contiguous bored piles to support the excavation. (A)]]></description>
      <pubDate>Thu, 31 Jul 2014 10:07:13 GMT</pubDate>
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