Journal articles
Author(s) | Title | Journal | Issue | Page | Category |
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Cordes, Tobias; Reinhold, Chris; Schneider-Muntau, Barbara; Grüllich, Sebastian; Himmelsbach, Christian; Wehrmeyer, Gerhard | Analyses of TBM disc cutter forces - application possibilities / Analyse der TBM-Diskenkräfte - Anwendungsmöglichkeiten | Geomechanics and Tunnelling | 5/2019 | 586-594 | Topics |
AbstractForecasts made during tunnelling of the daily advance, to control the machine, specify the lining and verify system behaviour are of great importance for safety and for the success of the whole project. In practice, such forecasts are obtained in deep tunnels by probe drilling, leading to downtime periods and by analog/digital face documentation with shorter downtime periods. Measurement and evaluation of rock mass cutting at the cutterhead of the TBM enables continuous monitoring without downtime. From the spatial distribution of the disc forces, basic geological/geotechnical information about the tunnel face can be derived. In addition, this data is valuable for load monitoring and monitoring the condition of the discs to determine the optimal changing time. This contribution deals with a geological-geotechnical interpretation of the disc forces of the open TBM on contract H33 Tulfes-Pfons of the Brenner Base Tunnel. The spatially distributed disc forces are evaluated and compared with the geological documentation. x | |||||
Braun, Matthias; Obiala, Renata; Odenbreit, Christoph | Analyses of the loadbearing behaviour of deep-embedded concrete dowels, CoSFB | Steel Construction | 3/2015 | 167-173 | Articles |
AbstractThe development of the “CoSFB-Betondübel” is presented in this paper. The “CoSFB-Betondübel” is a deep-embedded concrete dowel connecting in situ concrete with a steel section to assure composite action and thus allow for composite beam design. The loadbearing behaviour and parameters influencing this behaviour were determined through experimental tests. Special focus was given to the influence of the ratio of the resistance of the concrete dowel to the concrete compression class. The evaluation of the results concluded in a National Technical Approval [1]. Further investigations were performed via FE analysis in ABAQUS. Further, 3D models with non-linear material and geometry were prepared and validation undertaken. In addition, a real application example of CoSFB is shown. x | |||||
Graubner, Carl-Alexander; Koob, Benjamin | Analysis and comparison of the NDPs of various national annexes of Eurocode 6 / Analyse und Vergleich der NDPs verschiedener nationaler Anhänge zu Eurocode 6 | Mauerwerk | 6/2015 | 427-440 | Fachthemen |
AbstractIn the national annexes of Eurocode 6, the individual European Member States can define values for nationally determined parameters in various places or add regulations which are not in contradiction to the current European provisions. Consequently - despite a harmonized Eurocode 6 - the normative regulations of the individual Member States differ more or less. However, in the sense of practicability of the standards in Europe, it should be the aim to develop a European standard which is as uniform as possible and which has not to be applied in significantly different ways due to the national regulations. In order to better understand the interests of the other Member States for future generations of standards and to derive potentials of harmonization, the values of the Nationally Determined Parameters (NDPs) of various Member States are compared in this paper. In this context, the extent of the deviations between the different national annexes is examined and on this basis a possible potential of harmonization is identified. x | |||||
Analysis and Optimum Design of Metal Structures (Farkas, J. und Jármai, K.) | Stahlbau | 5/1998 | 400 | Bücher | |
Pittino, Philipp; Hafellner, Hans | Analysis and refurbishment of damp cellar walls / Untersuchung und Sanierung eines feuchten Kellermauerwerks (Gutachten) | Mauerwerk | 4/2019 | 232-245 | Berichte |
AbstractIn the following expertise report, the existing condition of the cellar of a semi-detached house, which was built in a coupled construction, is analysed and considerations for a hygric refurbishment are discussed. First and foremost, it was necessary to find the cause of the damp present in the outside walls of the cellar of the building. In order to describe the current characteristics of the building, an inventory analysis was made of obvious building defects. This is summarised and described in the following report, which was the basis for all further proceeding. Building physics measurements and evaluations were carried out, building materials were examined for their physical properties and corresponding evaluations and analyses were carried out. Finally, all measurement results and findings were collected to provide a conclusive explanation for the existing defects to the building fabric of the building. This in turn was the foundation for all further measures to be taken in order to determine the necessary remediation concepts and changes to the interior design or the use of the rooms. The aim was to make the cellar space fully usable again and to be able to hand over a list of proposals for the necessary technical remediation measures to the client. x | |||||
Drobiec, ?ukasz | Analysis of AAC walls subjected to vertical load / Analyse von vertikal belasteten Porenbeton-Wänden | Mauerwerk | 6/2019 | 387-403 | Berichte |
AbstractThe paper describes the results of testing six autoclaved aerated concrete (AAC) walls on a natural scale. The walls were made of 18 cm wide blocks and thin layer joints. Reinforced and non-reinforced walls were tested. Basalt grids and typical steel reinforcement (truss type) were used as reinforcements. The load was applied by a reinforced concrete rim beam. In the first part of the tests, the impact of the opening (window) on stress distribution and the load capacity of the wall was analysed. In the second part of the tests, the unequally loaded connection zone of perpendicular walls was analysed. The results were used to draw practical conclusions on rules of additional reinforcement of zones surrounding openings and connection zones of perpendicular walls. x | |||||
Rossi, Pierre; Daviau-Desnoyers, Dominic; Tailhan, Jean-Louis | Analysis of cracking in steel fibre-reinforced concrete (SFRC) structures in bending using probabilistic modelling | Structural Concrete | 3/2015 | 381-388 | Technical Papers |
AbstractAn improvement to the probabilistic discrete cracking model for fibre-reinforced concretes, originally developed by Rossi, is proposed in this paper. x | |||||
Analysis of fatigue test data to reassess EN 1993-1-9 detail categories | Stahlbau | 12/2020 | 1002 | Empfehlungen der Redaktion | |
Bartsch, Helen; Drebenstedt, Karl; Seyfried, Benjamin; Feldmann, Markus; Kuhlmann, Ulrike; Ummenhofer, Thomas | Analysis of fatigue test data to reassess EN 1993-1-9 detail categories | Steel Construction | 4/2020 | 280-293 | Articles |
AbstractThis paper addresses the assessment of fatigue details according to EN 1993-1-9, which form the basis of the most important fatigue verification, the nominal stress approach. First of all, a suitable statistical methodology had to be defined for consistent detail classification. A structured database on the MySQL platform serves as a basis for the evaluation of the detail categories. In addition to fatigue test data documented in the background document to EN 1993-1-9, this database also includes new test data provided by the authors. After selecting the most meaningful test data, important details, such as longitudinal welds, were reassessed. In addition, the authors carried out fatigue tests in connection with numerical simulations in order to be able to evaluate the fatigue strength with better accuracy. The results so far show that the details analysed often prove to have a higher fatigue strength than currently documented in EN 1993-1-9. x | |||||
Wu, Xun; Wu, Taotao; Chen, Weizhen | Analysis of height difference between three trusses of a steel truss bridge during incremental launching | Stahlbau | 9/2018 | 910-922 | Fachthemen |
AbstractAn incremental launching method with the advantages of saving construction space, a less complicated construction programme and fast construction speed has been widely used in engineering. Huanghe Bridge is a double-deck rail-and-road steel truss bridge with stiffened suspension cables; the incremental launching method was used for this bridge. A height difference between the three main trusses caused by an assembly error can result in large reaction forces in one or two slide shoes under the three main trusses during the launch because the bridge is very heavy, which can make the stresses in the main bridge and the temporary supports exceed the allowable stress, which would be harmful to the bridge construction. To study the influences of height-difference changes on the stresses in the entire bridge including the temporary supports, a finite element simulation is used to analyse the global and local stresses of the entire bridge. The results show that if the height difference is outside the range +20 mm to -30 mm, the stresses in the temporary supports near the pier will exceed the allowable stress during the launch. The height-difference values of the three trusses should therefore be restricted to ensure the safety of the construction. The limit values of the height difference are confirmed using a finite element model of the entire bridge. Moreover, in the local finite element model, the local structure is within the safety range when the confirmed height difference occurs, which ensures the rationality of the confirmed height difference values. The results of the finite element simulation are approximately the same as those of an actual measurement performed during the launch, and the reasonable limit values for the height difference between three trusses are +15 mm and -25 mm respectively. These limit values are the construction control values provided for the construction unit. Finally, solutions to decrease the influence of the height difference are given. x | |||||
Kerr, A. D. | Analysis of plates that rst on expansive subgrades (Berechnung von Platten auf quellfähigem Untergrund). | Bautechnik | 7/1996 | 447-453 | Fachthemen |
AbstractZuerst wird die Entwicklung der Forschung zu der Thematik kurz beschrieben. Das vorgestellte Berechnungsverfahren basiert auf der Annahme, daß die Wirkung des Quellens oder Schwindens von Böden durch eine Vorverformung des Baugrundmodells simuliert werden kann. Zwei spezifische Probleme werden formuliert und Lösungen angeboten: 1. Die Platte hat vollen Kontakt mit dem Boden; 2. Die Platte löst sich von der Unterlage. Mit den erhaltenen geschlossenen Lösungen werden die analytischen und mechanischen Zusammenhänge der vorgeschlagenen Lösungsmethode zur Berechnung von Konstruktionen erläutert, die auf expansivem Boden gegründet sind. x | |||||
Vassilev ?, Todor; Salehi, Hamidreza | Analysis of rectangular cross sections under double eccentric compression stress / Spannungen im Rechteckquerschnitt mit versagender Zugzone bei doppelt exzentrischem Druck | Mauerwerk | 1/2018 | 44-49 | Berichte |
AbstractDouble eccentrically loaded cross-sections with failing tension zone occur both in foundation engineering and in masonry building. The case of walls or columns loaded with double eccentricity by a normal force was no longer covered under the global safety concept of DIN 1053-1 and is thus not normally considered in practice. With the transition to the semi-probabilistic safety concept, verification of the cross-section at the limit state of loadbearing capacity is performed near or at the failure state. This also made it necessary as part of the introduction of EN 1996-1-1 to introduce a verification for double eccentrically loaded cross-sections. The present article considers the non-linear stress distribution in double eccentrically loaded cross-sections and the resulting position of the neutral axis. The described process is numerically robust and can be implemented with little effort for the analysis of masonry as an Excel spreadsheet. x | |||||
Stempfle, Hartwig; Weber, Marius; Wipfli, Manuel | Analysis of steel-reinforced masonry walls regarding maximum shear loads / Traglastberechnung von vertikal bewehrten Mauerwerksscheiben | Mauerwerk | 3/2016 | 232-242 | Fachthemen |
AbstractLoadings on masonry for the earthquake case pose particular challenges for the material. In order to improve the load-bearing and deformation behaviour, masonry building elements can be strengthened with reinforcement. This article presents an analytical model for the calculation of the load-bearing capacity of vertically reinforced masonry panels. The masonry is modelled as a homogeneous and anisotropic material and failure conditions are based on the plastic theory. Using uniaxially loaded stress fields and considering the structural constraints, a lower load-bearing threshold can be given. In order to verify the model, three shear tests on reinforced sand-lime block masonry were recalculated regarding their load-bearing capacity. The test panels each contained vertical steel reinforcement in the blocks. The blocks were laid in thin bed mortar. x | |||||
Bianchi, Gianpino Walter | Analysis of TBM parameters during tunnelling in adverse conditions - The case study of the Frejus Safety Tunnel, Western Alps | Geomechanics and Tunnelling | 1/2023 | 47-52 | Topics |
AbstractOne of the main hazards during tunnel boring machine (TBM) excavation in hard rock is related to the occurrence of unforeseen adverse conditions, leading to unfavourable rock mass behaviour during tunnel boring. In this respect, the continuous analyses of TBM excavation parameters may represent an interesting tool for a continuous monitoring of geotechnical conditions at the tunnel face and for early detection of changing ground conditions in the rock mass. This work provides a back-analysis of TBM data recorded during the excavation of the Frejus Safety Tunnel, bored across the French-Italian border in the Western Alps. It is a 13 km-long tunnel excavated by a 9.4 m diameter, single-shield TBM through strongly anisotropic calcareous schist, with cover up to 1800 m. Main problems faced during TBM excavation were related to the local occurrence of buckling-related convergence and consequent asymmetrical loading on the precast segment rings. Correlating TBM performance parameters to the encountered geological and geomechanical conditions provides the possibility to identify which parameters are most affected by geomechanical properties of the rock mass at the tunnel face and by rock mass behaviour. Conversely, the analysis indicates which parameters can be adopted as monitoring tool of ground conditions during TBM advance. In addition, this work highlights how buckling phenomena can be distinguished, in terms of TBM operation and performance, from other adverse conditions as, e.g., blocky ground or squeezing. x | |||||
Alani, Amir M.; Aboutalebi, Morteza | Analysis of the subgrade stiffness effect on the behaviour of ground-supported concrete slabs | Structural Concrete | 2/2012 | 102-108 | Articles |
AbstractThis paper confirms that the structural behaviour of ground-supported slabs is a non-linear function of the structural properties of slabs as well as the supporting soil. The findings reported emphasize that the suggested equations used in design codes pay insufficient attention to the effect of the supporting ground stiffness within the context of the mechanical behaviour of slabs as far as ductility is concerned. The results presented demonstrate that ground stiffness has a significant effect on the ductility of ground-supported slabs. It also pays particular attention to the possibility of determining the ductility limit of slabs. x | |||||
Großauer, K.; Schubert, W. | Analysis of Tunnel Displacements for the Geotechnical Short Term Prediction | Geomechanik und Tunnelbau | 5/2008 | 477-485 | Fachthemen |
AbstractMeasurement of displacements in tunnels is primarily used for the assessment of the stabilization process and the verification of the system behaviour. In addition the displacement data can be used for the prediction of changing ground conditions ahead of the face. For this purpose, the evaluation of displacement vector orientation turned out to be the most appropriate method. Several authors showed the influence of the excavation on the stress and displacement field when tunnelling through zones of different stiffness. One of the main findings was that the displacement vector orientation significantly changes when the excavation approaches ground with different deformability. Hence, it was concluded that the development of the spatial orientation of the displacement vector can be used for the prediction of the ground conditions ahead of the face. The main results of the investigations performed are summarized in this paper. The evaluation of data from three different case histories is shown in order to encourage the use of advanced displacement data evaluation. x | |||||
Belletti, Beatrice; Damoni, Cecilia; Hendriks, Max A. N.; de Boer, Ane | Analytical and numerical evaluation of the design shear resistance of reinforced concrete slabs | Structural Concrete | 3/2014 | 317-330 | Technical Papers |
AbstractThe aim of this research is to compare the predictions of the design load-carrying capacity of slabs obtained with simplified analytical and numerical procedures which can be readily used by analysts in the current design process. The research fits into a research programme initiated by the Dutch Ministry of Infrastructure and the Environment for the re-examination of the load-carrying capacity of existing bridges and viaducts, and the beams and slabs they include, through the use of non-linear finite-element analyses. The behaviour of reinforced concrete slabs subjected to concentrated loads close to their supports is investigated in this contribution. Three tests from a series of 18 slabs with a total of 108 tests, tested at Delft University of Technology, were selected as case studies and analysed with non-linear finite-element analyses and analytical models either proposed by design codes or available in the literature. The research agrees well with the philosophy of the fib Model Code for Concrete Structures 2010, which offers different analytical and numerical calculation methods for evaluating the design shear resistance of reinforced concrete members according to different levels of approximation. For the three slabs investigated in this study, it indeed pays to use higher levels of approximation. The highest level (level IV) based on non-linear finite element analysis gives the highest design load resistance, but still well below the resistance obtained experimentally. x | |||||
Gloimüller, Stefan; Pánová, Petra; Lang, Georg | Analytical and numerical load evaluation from excavation shoring on the powerhouse Kirchbichl / Analytische und numerische Belastungsermittlung aus Baugrubenumschließung auf das Krafthaus Kirchbichl | Geomechanics and Tunnelling | 5/2020 | 566-573 | Topics |
AbstractTiroler Wasserkraft AG realized the extension of hydropower plant Kirchbichl located in the Unterinntal built in the 1940s for the first time. The excavation pits were retained by a bored pile wall with jet grouting connections between the piles, supported with up to two bracing horizons. Safety against uplift during construction stage is managed by a deep-set jet grouting plate, which is partially anchored. Due to the dismantling of the bracing during the construction progress a partially load transfer from the bored pile wall on the partly completed concrete construction and the jet grouted plate occurs. This interaction is simulated at the static calculations. The excavation shoring was calculated by using a geotechnical program. The resulting spring supporting forces from geotechnical consideration were used in the finite element model as loads on the new reinforced concrete walls to calculate the necessary reinforcement content during construction sequence. The results from construction sequence were perpetuated at final state of the new powerhouse structure to get the governing reinforcement content. x | |||||
Niederegger, P.; Knobloch, M.; Fontana, M. | Analytical calculation model for unstiffened elements with nonlinear stress-strain relationships under uniform compression | Steel Construction | 1/2009 | 42-49 | Articles |
AbstractThis paper presents an improved analytical calculation model for unstiffened elements with nonlinear stress-strain relationships (e.g. aluminium and stainless steel) subjected to uniform in-plane compression. The model takes material nonlinearity into account by means of the Ramberg-Osgood constitutive law. It is based on the results of a numerical parametric study of the load-carrying behaviour of unstiffened elements. A comparative study shows good agreement between test results and analytically determined strengths according to the new calculation model. x | |||||
Seidel, Marc | Analytical calculation of stress concentrations at welded flange necks | Stahlbau | 6/2020 | 551-560 | Aufsätze |
AbstractRing flange connections for tubular towers, such as those for wind turbines or chimneys, are subjected to significant fatigue loading. Apart from the bolts, it is also necessary to carry out a fatigue analysis of the weld connecting the flange to the tower shell. Owing to the presence of the flange, local bending moments occur in the shell which increase the nominal (membrane) stresses, i. e. stress concentrations occur. This paper presents an analytical model for calculating these local bending moments such that stress concentrations can be determined. The analytical model was compared with results from 3D finite element models, and good agreement was found. The results from the model presented are thus deemed appropriate for design purposes. x | |||||
Delnavaz, Ali; Hamidnia, Mohammad | Analytical investigation on shape configuration of CFRP strips on lateral loading capacity of strengthened RC shear wall | Structural Concrete | 6/2016 | 1059-1070 | Technical Papers |
AbstractIn the past few years, the use of carbon fibre reinforced polymer (CFRP) has increased, because of their high strength, in concrete elements such as shear walls. In this study, the behaviour of a shear wall strengthened with different layout configurations of CFRP under lateral loading was investigated. For this purpose, a model is first verified in laboratory work, then in the next step the models were analysed by increasing the number of fibre layers and the effect of fibre layers on shear wall capacity was studied. Sliding between fibres and concrete was neglected. Also the effect of increasing the concrete strength of a reinforced concrete (RC) wall on CFRP strengthening was studied. In all models, comparisons were made between the results of CFRP configurations in increasing lateral strength and also ductility. Finally, by comparing the results, the best fibre configuration was determined based on the maximum load capacity. x | |||||
Tenpierik, M.; van der Spoel, W.; Cauberg, H. | Analytical Model for Predicting Thermal Bridge Effects due to Vacuum Insulation Panel Barrier Envelopes | Bauphysik | 1/2008 | 38-45 | Fachthemen |
AbstractBecause of a necessity for sustainability and thus for a reduction of the amount of primary energy generated with fossil fuels, vacuum insulation panels (VIP) have recently caught the attention of practitioners in the building industry. The reduction of layer thickness may be considered among the most promising features for large-scale application of VIPs in buildings. The high barrier laminate (or casing) with relatively high thermal conductivity envelops the core material, thus introducing a thermal bridge at the panel edges and corners. Especially for barrier laminates containing ?thick? metal foils, the thermal bridge effect needs to be considered thoughtful. In this contribution analytical models are presented which on the one hand allow rapid estimation of the VIP?s overall thermal performance and on the other hand show the influence of material and geometric parameters on this performance. The analytical models are validated through numerical simulations. x | |||||
Hussein, Luaay; Amleh, Lamya | Analytical modelling of bond stress at steel-concrete interface due to corrosion | Structural Concrete | 4/2016 | 541-552 | Technical Papers |
AbstractAn analytical model is proposed for bond stresses at the corroded steel-concrete interface in reinforced concrete. The concrete around the corroded bar is modelled as a thick-walled cylinder - consisting of an inner cylinder of an anisotropic material and an outer cylinder made of an isotropic material - subjected to internal pressure exerted by the growth of corrosion products on the concrete wall at the interface. A frictional model is used to combine the action of confining pressure due to radial pressure produced by principal bar ribs and the pressure resulting from expansion of corrosion products. The analysis results using the proposed model show good agreement with the experimental results of several researchers. x | |||||
Hanawa, Y.; Bergmann, R. | Analytical study on the shearing force share of I-shaped beam with reinforced concrete between the flanges (Analytische Untersuchung zur Querkraftverteilung bei I-Profilen mit ausbetonierten Kammern) | Stahlbau | 3/2000 | 184-190 | Fachthemen |
AbstractDas Tragverhalten von I-Profilen mit Betonfüllung zwischen den Flanschen wird analytisch untersucht. Durch Ansatz von Reibung zwischen Stahl und Beton mit realistischen Reibungskoeffizienten kann das Verbundverhalten des Trägers simuliert werden. Die Aufteilung einer Querkraft in Stahlprofil- und Betonanteil wird ermittelt. Dabei werden Einflüsse aus Schublänge, Querschnittshöhe und Normalkraftwirkung untersucht. x | |||||
Perau, Eugen; Meteling, Nils | Analytisch formulierte Näherungslösungen zur Grundwasserströmung bei einer Restwasserhaltung | geotechnik | 1/2017 | 2-14 | Fachthemen |
AbstractBei der Erstellung von Baugruben im Grundwasser ist es sinnvoll, die Verbauwände in eine schwächer durchlässige Bodenschicht einzubinden und eine Restwasserhaltung zu betreiben. Da bei einer solchen Konstruktion die Verbauwände unterströmt werden, entsteht ein Strömungsfeld, das für verschiedene Berechnungen und Standsicherheitsnachweise ermittelt werden muss. So müssen z. B. hydraulische Gradienten, Filtergeschwindigkeiten sowie Potenziale und Porenwasserdrücke bestimmt werden. Diese werden zur Ermittlung der Wandbelastung aus Erd- und Wasserdruck, bei den Nachweisen gegen hydraulischen Grundbruch, gegen innere Erosion, gegen Versagen des Erdwiderlagers sowie zur Bestimmung des Grundwasserzuflusses verwendet. x |