Artikeldatenbank
Autor(en) | Titel | Zeitschrift | Ausgabe | Seite | Rubrik |
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Großauer, K.; Schubert, W. | Analysis of Tunnel Displacements for the Geotechnical Short Term Prediction | Geomechanik und Tunnelbau | 5/2008 | 477-485 | Fachthemen |
KurzfassungMeasurement 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 | |||||
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 |
KurzfassungThis 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 | |||||
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 |
KurzfassungOne 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 | |||||
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 |
KurzfassungLoadings 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 | |||||
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 |
KurzfassungDouble 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 | |||||
Kerr, A. D. | Analysis of plates that rst on expansive subgrades (Berechnung von Platten auf quellfähigem Untergrund). | Bautechnik | 7/1996 | 447-453 | Fachthemen |
KurzfassungZuerst 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 | |||||
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 |
KurzfassungAn 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 | |||||
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 |
KurzfassungThis 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 | |||||
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 |
KurzfassungAn improvement to the probabilistic discrete cracking model for fibre-reinforced concretes, originally developed by Rossi, is proposed in this paper. x | |||||
Drobiec, ?ukasz | Analysis of AAC walls subjected to vertical load / Analyse von vertikal belasteten Porenbeton-Wänden | Mauerwerk | 6/2019 | 387-403 | Berichte |
KurzfassungThe 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 | |||||
Pittino, Philipp; Hafellner, Hans | Analysis and refurbishment of damp cellar walls / Untersuchung und Sanierung eines feuchten Kellermauerwerks (Gutachten) | Mauerwerk | 4/2019 | 232-245 | Berichte |
KurzfassungIn 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 | |||||
Analysis and Optimum Design of Metal Structures (Farkas, J. und Jármai, K.) | Stahlbau | 5/1998 | 400 | Bücher | |
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 |
KurzfassungIn 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 | |||||
Braun, Matthias; Obiala, Renata; Odenbreit, Christoph | Analyses of the loadbearing behaviour of deep-embedded concrete dowels, CoSFB | Steel Construction | 3/2015 | 167-173 | Articles |
KurzfassungThe 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 | |||||
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 |
KurzfassungForecasts 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 | |||||
Wannenmacher, Helmut; Schlicke, Marcel | Analyses of Pre-Excavation Grouting for TBM Tunnelling | Geomechanics and Tunnelling | 1/2023 | 55-59 | Topics |
KurzfassungPre-excavation grouting (PEG) is essential for mitigating groundwater inflow to unlined tunnel structures. Prevention of initial water inflow proved best practice to balance groundwater conditions throughout the utilisation of a tunnel. The grouted rock mass acts as a circumferential sealing barrier instead of a secondary lining to minimise groundwater inflow to an acceptable level over the structure's lifetime. The construction of unlined tunnels relies on existing favourable in-situ rock mass conditions with an overall low hydraulic head, mainly to keep the effort of grouting inferior and avoid an unbalanced proportion of pre-excavation grouting during the tunnel construction works. x | |||||
Drobiec, Lukasz | Analyse von Spannungen und Verformungen im Brüstungsbereich von Wandmodellen aus Porenbeton und Kalksandstein | Mauerwerk | 1/2020 | 2-16 | Fachthemen |
KurzfassungIn dem vorliegenden Beitrag wurden Ergebnisse der Prüfungen von großformatigen Wandmodellen mit zwei Fensteröffnungen dargestellt. Wände aus Porenbeton und Kalksandstein wurden getestet. Die Wände wurden unter Verwendung von Dünnbettmörtel bei unvermörtelten Stoßfugen errichtet. Die Arbeit entspricht den zuvor durchgeführten Tests. Die Verifikation der Ergebnisse aus der Untersuchung kleinerer Modelle war das Ziel der Forschung [12, 13]. Spannungen und Verformungen der Modelle wurden analysiert und mit kleineren Modellen verglichen. Aufgrund der Analyse der Spannung-Verformung-Diagramme wurde ermittelt, dass die horizontale Spannung im Brüstungsbereich circa 0,2 MPa beträgt. Es wurden Berechnungen der geprüften Wände unter Anwendung eines Programms vorgenommen, das auf der Finite-Elemente-Methode basiert. Die Analyse der Ergebnisse von Laborprüfungen und numerischen Simulationen ermöglichte, das Niveau von Spannungen und Verformungen der geprüften Wände zu ermitteln. x | |||||
Oppeneder, Johannes; Dittmar, Frank; Tue, Nguyen Viet | Analyse von Beton-Stahlrohrsteckverbindungen für Maste - Großversuche und FEM-Simulationen | Beton- und Stahlbetonbau | 12/2020 | 980-993 | Aufsätze |
KurzfassungDie Beton-Stahlrohrsteckverbindung wird in dieser Arbeit für die Anwendung bei hybriden Mastkonstruktionen aus der Stahlrohrsteckverbindung weiterentwickelt. Die maßgebende Biegebeanspruchung der Maste wird dabei vom Stahlrohr mit Schubrippen über die Mörtelfuge in das darunterliegende Schleuderbetonrohr eingeleitet. Der Kraftfluss in der Verbindung ändert sich fortlaufend mit der Lastzunahme und wird entscheidend vom Verformungsverhalten der Rohre beeinflusst. Das Trag- und Verformungsverhalten der neuen Verbindung wird in diesem Beitrag anhand zweier durchgeführter Großversuche und begleitender FEM-Simulationen untersucht. Des Weiteren wird anhand zweier variierter Parameter, der Position der Schubrippen sowie einer Steckverbindung ohne Schubrippen der Einfluss auf das Trag- und Verformungsverhalten ermittelt und diskutiert. x | |||||
Analyse von Bauschäden: Bauinstallationen Bauchemie und Bauphysik populärverständlich | Bautechnik | 1/2000 | 87 | Termine | |
Vogdt, F. U.; Kochendörfer, B.; Dittmar, A. | Analyse und Vergleich energetischer Standards anhand eines exemplarischen Einfamilienhauses bzgl. Energiebedarf und Kosten über den Lebenszyklus | Bauphysik | 5/2010 | 319-326 | Fachthemen |
KurzfassungIm Kontext einer nachhaltigen Entwicklung konnten in den letzten Jahren vor allem im Neubaubereich eine Reihe von Fortschritten erzielt werden. Besonders hervorzuheben ist die Weiterentwicklung von Technologien zur Nutzung regenerativer Energien und neuer Baustoffe mit besonders geringer Wärmeleitfähigkeit. Parallel wurden Konzepte für Niedrigheizenergie- bis hin zu Passiv- und sogar Plusenergiehäuser entwickelt und umgesetzt. Diese Gebäudestandards weisen einen geringen Heizenergiebedarf auf und ermöglichen so erhebliche Energieeinsparungen während der Gebäudenutzungsphase. Es stellt sich die Frage, ob sich durch die Verwendung von neuen Technologien und Baustoffen ein Teil des Gesamtprimärenergiebedarfs von der Nutzungs- in die Erstellungs- und Instandhaltungsphase verlagert. Fraglich ist dabei auch, welche Mehrinvestitionen den erwarteten Betriebskosteneinsparungen gegenüberstehen. Um dies zu untersuchen, wurden exemplarisch für ein freistehendes Einfamilienhauses mehrere Ausführungsvarianten geplant und eine Lebenszyklusanalyse mit dem Programmwerkzeug LEGEP durchgeführt. Auf dieser Grundlage können für das exemplarische Einfamilienhaus Aussagen hinsichtlich des lebenszyklusübergreifenden Primärenergiebedarfs sowie der Kostenentwicklung getroffen werden. Die Ergebnisse haben jedoch keinen allgemeingültigen Charakter. Sie machen deutlich, dass im Sinne eines nachhaltigen Ressourceneinsatzes für den Einzelfall nur eine ganzheitliche Betrachtung zielführend ist. x | |||||
Burmeister, H.; Keller, B. | Analyse und Darstellung der Wechselwirkung zwischen Klima und Gebäude: Klimaflächen, Teil 2: Interpretation und strategische Aussagen | Bauphysik | 2/1997 | 46-49 | Fachthemen |
KurzfassungDie Leistungsfähigkeit der Methode der Klimaflächen wird an verschiedenen Beispielen dargelegt: die Interpretation für den Heizenergiebedarf und die Auslegungsleistung, deren Variation über eine Zehnjahresperiode, die Darstellung und die Auswirkung des Einflusses von inneren Quellen, die Bedeutung und Auswirkung der Nachtabsenkung, die energetische Gesamtoptimierung von Gebäuden. Zu allen diesen Aspekten werden eine Reihe von abschließenden und allgemeingültigen Aussagen von strategischer Bedeutung für die Gebäudeplanung gemacht. x | |||||
Burmeister, H.; Keller, B. | Analyse und Darstellung der Wechselwirkung zwischen Klima und Gebäude: Klimaflächen - Teil 1: Grundlagen | Bauphysik | 1/1997 | 1-6 | Fachthemen |
KurzfassungDurch die exakte Lösung der Leistungsbilanzdifferentialgleichung eines Raumes ist es gelungen, seine thermische Beschreibung auf nur drei Parameter zu reduzieren, die sich unter Berücksichtigung der speziellen Gesetzmäßigkeiten instationärer Prozesse in einem für die Berechnung des Energie- und Leistungsbedarfs verallgemeinerten Verlustfaktor und eine Kombination von den zwei Kenngrößen Zeitkonstante und Gewinn-/Verlustverhältnis aufteilen. Mit beiden letzteren läßt sich eine verallgemeinerte Heizgradfunktion als dreidimensionale Klimafläche darstellen. Analog läßt sich für den Auslegungsbedarf eine dreidimensionale Auslegungstemperaturfläche herleiten. Beide Flächen gestatten die energetische Positionierung eines Raumes durch seine zwei Kennparameter und die direkte Ablesung seines Energie- oder Leistungsbedarfs. x | |||||
Wehnert, M.; Neher, H. P.; Vermeer, P. A.; Zangl, L. W.; Dzengel, M. | Analyse des Verformungsverhaltens einer Hausmülldeponie | Bautechnik | 4/2005 | 218-226 | Fachthemen |
KurzfassungDas Verformungsverhalten der Hausmülldeponie Berg in Rheinland-Pfalz wird in diesem Aufsatz mit Hilfe der Methode der finiten Elemente analysiert. Das mechanische Verhalten des Mülls wird mit dem sogenannten Soft-Soil-Creep Modell, einem elasto-viskoplastischen Stoffgesetz, modelliert. Für das mechanische Verhalten der restlichen Schichten wird das Mohr-Coulomb Modell verwendet. Die beiden Stoffgesetze werden nach einer Einführung in die Problematik kurz vorgestellt. Bevor die Ergebnisse der Analyse diskutiert und mit Messwerten verglichen werden, wird die Erstellung des Modells und die Ermittlung bzw. Kalibrierung der Parameter für die FE Berechnung beschrieben. x | |||||
Steinborn, T. | Analyse des universitären Lern- und Arbeitsverhaltens von Studierenden des Bauingenieurwesens | Stahlbau | 4/2008 | 318 | Dissertationen |