Papers by Konrad Bergmeister
Wiley-VCH Verlag GmbH eBooks, Apr 14, 2014
Bridge maintenance, safety and management, Jun 21, 2012
Arch bridges made from nature stone nowadays are the oldest structures which are still in use on ... more Arch bridges made from nature stone nowadays are the oldest structures which are still in use on road and railway lines. With an average age of more than hundred years, these structures often are seen as historical important buildings. Most of them had been constructed during the great building period of roads and railways from the 1840ies to 1900. Lots of the considered nature stone bridges are constructed as circle or three center curve, some of them also in a parabolic form or catenaries or cycloide. The height of the apex cover varies in a large range. If masonry was appropriated, usually sand, chalkstone or clay bricks were used. For most bridges no observations of the material parameter are available, as a result the stone and the mortar strengths are unknown. Under the usage of the German railway company, there are more than 8000 arch bridges yet, although at local roads there is an additional unknown number of them. In Austria, the railway network, especially along the southern railway line has around 1000 arch bridges in usage. In whole Europe, the stock of masonry railway bridges is estimated with around 70.000. In the course of route expansion plans in the past especially arch bridges have been replaced by new steel or reinforced concrete structures. Considerations of preservation, the budgetary situation of the rail and road operators, as well as a sustainable, resource efficient usage of resources and existing infrastructure are motivations to maintain and-if necessarytoughen up existing arch bridges. Therefore, the issues of sustainability, durability and serviceability become more important.
CRC Press eBooks, Jul 7, 2010
In structural bridge engineering maintenance strategies and thus budgetary demands are highly inf... more In structural bridge engineering maintenance strategies and thus budgetary demands are highly influenced by the quality of design in general as well as the chosen construction type in particular. Nowadays bridge owners and planers tend to include life-cycle cost analyses in their decision processes regarding the overall design trying to optimize structural detailing with respect to robustness, durability and exchangeability of certain structural members. However efforts to reduce maintenance costs over the expected lifetime by adopting well established design principles leads to unknown risks concerning for instance boundary conditions. Monitoring solutions can reduce the associated risk of new design concepts by constant supervision of critical structural characteristics and in combination with data analyses allows for the verification of new numerical and analytical models. This paper especially focuses on the analysis of monitoring data obtained by an integrative multi-sensor-monitoring system targeting the soil-structure interaction of frame bridges.
CRC Press eBooks, Jul 19, 2011
Monitoring is of most practical significance for the design and assessment of new and existing en... more Monitoring is of most practical significance for the design and assessment of new and existing engineering structures. Practical experience and observations show that monitoring can provide the basis for new code specifications or efficient maintenance programs. Moreover, monitoring systems can avoid considerable costs of repairs and inconvenience to the public due to interruptions. This gives rise to the need for a thorough investigation to achieve an effective implementation of recorded monitoring data in numerical or analytical structural models that allow the detection of a deviant behavior from the proposed and the detection of initial deterioration processes. This study attempts to derive a concept for the effective incorporation of monitoring information in numerical models based on the concept of model correction factors. In particular, these studies are performed on the abutment free bridge structure S33.24 that has been proof loaded and monitored since December 2008. A merit of models derived based on monitoring data is that it is directly related to performance indicators that can be used for the assessment of the existing structural capacity and for an efficient life cycle analysis.
Structural Concrete, Nov 11, 2014
When it comes to dynamically loaded concrete structures, determining the real degree of fatigue d... more When it comes to dynamically loaded concrete structures, determining the real degree of fatigue damage of a structure on site is a very demanding process that has not been explored in depth. Calculation concepts according to current codes and specifications (e.g. fib Model Code for Concrete Structures 2010 [1]) do not offer efficient results for this task. However, the permanent monitoring from the erection of a structure up to the end of its lifetime is seen as a very promising possibility for assessing the degree of damage constantly. This article takes a closer look at the concrete fatigue concept of fib Model Code 2010 [1], shows an FE simulation of a time-dependent fatigue process for an offshore wind turbine foundation and presents a fatigue monitoring concept including laboratory tests, which enables the detection of the real degree of deterioration in a concrete structure. During tests, the use of ultrasound was identified as the most appropriate method. Measuring wave velocity enables the determination of the dynamic E-modulus, which correlates to the degree of damage within the cross-section of the structure considered.
Beton- Und Stahlbetonbau, 2011
ABSTRACT In zwei Beiträgen wird ein auf der Zuverlässigkeitstheorie basierendes probabilistisches... more ABSTRACT In zwei Beiträgen wird ein auf der Zuverlässigkeitstheorie basierendes probabilistisches Verfahren für eine schnelle Bewertung der Tragfähigkeit eines geschädigten Stahlbetonbrückenbauwerks vorgestellt. Es ersetzt keine statische Nachberechnung, unterstützt jedoch den Bauwerksprüfer noch während der Prüfung gemäß DIN 1076 und lässt eine schnelle Entscheidung über die Art und Weise einer ggf. erforderlichen Nutzungseinschränkung noch vor einer Nachberechnung zu. Mit dem Verfahren ist es möglich, eine verbesserte Bewertung über die Auswirkung von Schäden und Mängeln an Stahlbetonbrücken auf deren Tragfähigkeit im Rahmen einer handnahen visuellen Bauwerksprüfung zu erreichen. Teil 1 behandelt die Grundlagen des Verfahrens sowie die Entwicklung der veränderten stochastischen Material- und Geometrieparameter infolge Schädigung. In Teil 2 wird die Modellunsicherheit “Bauwerksprüfer” sowie das baupraktische Näherungsverfahren für eine Anwendung im Rahmen der RI-EBW-PRÜF vorgestellt.Basics and Development of Stochastic Models for a Structural Reliability Assessment of Reinforced Concrete Bridges on the Basis of the Results from Bridge InspectionA probabilistic method based on the reliability theory allows a quick assessment of the load bearing capacity of damaged reinforced concrete bridges. The aim is to support the bridge inspection engineer during the bridge inspection according to DIN 1076 and not to replace a static recalculation. It should allow a quick decision as to whether or not a restriction of the crossing traffic is necessary. With this method it is possible to achieve a better assessment of the influence of damages on reinforced concrete bridges which are seen in a visual bridge inspection. Part 1 of the two papers describes the basics of the methodology and shows the development of the stochastic models for the material and geometry parameters which have changed as a result of damage. In Part 2 the model uncertainty for the bridge inspector and the practical use in accordance with the RI-EBW-PRÜF are shown.
For some time now short-span bridges such as overpasses have been designed as frame structures in... more For some time now short-span bridges such as overpasses have been designed as frame structures in Austria. During this phase little problems have been observed with this type of design thus constantly pushing the popularity of this construction type towards application for increasingly longer structures. Caused by this development and the fact that such highly undetermined structures are very susceptible to constraint loads a series of research projects was set up. The main targets are an improved understanding of the soilstructure interaction, the effects of temperature loads, time dependent processes like creep and shrinkage as well as partial settlements. Apart from theoretical considerations and numerical simulations the primary objective is monitoring of actual structural response in particular the structure-soil-interaction of newly erected long frame bridges. In this paper a suitable integral monitoring concept for a three-span frame-structure is being introduced and the data preparation discussed.
Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH & Co. KG eBooks, Jul 30, 2009
Beton- Und Stahlbetonbau, Jan 31, 2011
Structure and Infrastructure Engineering, Aug 1, 2009
and-conditions-of-access.pdf This article may be used for research, teaching and private study pu... more and-conditions-of-access.pdf This article may be used for research, teaching and private study purposes. Any substantial or systematic reproduction, redistribution , reselling , loan or sub-licensing, systematic supply or distribution in any form to anyone is expressly forbidden. The publisher does not give any warranty express or implied or make any representation that the contents will be complete or accurate or up to date. The accuracy of any instructions, formulae and drug doses should be independently verified with primary sources. The publisher shall not be liable for any loss, actions, claims, proceedings, demand or costs or damages whatsoever or howsoever caused arising directly or indirectly in connection with or arising out of the use of this material.
Monitoring is highly important for the design and assessment of new and existing engineering stru... more Monitoring is highly important for the design and assessment of new and existing engineering structures. Moreover, monitoring systems can avoid considerable costs of repairs and inconvenience to the public due to interruptions. Therefore, a thorough investigation is needed to achieve an effective implementation of recorded monitoring data in numerical or analytical structural models that allow the detection of a deviant behavior from the proposed and the detection of initial deterioration processes. Using as example the abutment free bridge structure S33.24 this study attempts to derive a concept for the effective incorporation of monitoring information in numerical models based on the concept of sensitivity factors.
Beton- Und Stahlbetonbau, Mar 1, 2011
Im vorliegenden Teil 2 des Beitrags wird die Entwicklung des baupraktischen Näherungsverfahrens f... more Im vorliegenden Teil 2 des Beitrags wird die Entwicklung des baupraktischen Näherungsverfahrens für die Beurteilung der Zuverlässigkeit von Massivbrücken im Rahmen der RI-EBW-PRÜF [1] vorgestellt. Wesentlicher Inhalt ist dabei die Modellierung der Modellunsicherheit Bauwerksprüfer, da die Bewertung der Mängel und Schäden an einem Brückenbauwerk durch den jeweiligen Bauwerksprüfer einen entscheidenden Einfluss auf die Zustandsbewertung hat. Zudem wird auf die Dimensionsanalyse von Grenzzustandsfunktionen näher eingegangen, da damit bei geschickter Normierung eine allgemein gültige Anwendung des Verfahrens erreicht werden kann. Die Anwendung des Verfahrens erfolgt mit einem Software-Tool, das abschließend vorgestellt wird. In Teil 1 des Beitrags wurden die Grundlagen des Verfahrens sowie die Entwicklung der veränderten stochastischen Material-und Geometrieparameter infolge Schädigung behandelt. Development of an Approximation Procedure for a Structural Reliability Assessment of Reinforced Concrete Bridges on the Basis of the Results from Bridge Inspection Part 2 of the paper shows the development of the approximation procedure for the reliability assessment of reinforced concrete bridges according to RI-EBW-PRÜF [1]. An essential part of this is the development carried out by the model uncertainty bridge inspector, as the respective bridge inspector's individual assessment of the damage of a bridge has a decisive influence on the condition evaluation. Furthermore, the dimensional analyses of ultimate limit states are shown, as the general use of the developed methodology can be achieved with an ingenious standardization. The application of the procedure with the developed software tool is presented in conclusion. Part 1 of the two papers describes the basics of the methodology and shows the development of the stochastic models for the material and geometry parameters which have changed as a result of damage.
Wiley-VCH Verlag GmbH & Co. KGaA eBooks, Jul 22, 2009
Wiley-VCH Verlag GmbH & Co. KGaA eBooks, Jul 22, 2009
CRC Press eBooks, Jul 7, 2010
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Papers by Konrad Bergmeister