620 Ingenieurwissenschaften
Filtern
Erscheinungsjahr
Dokumenttyp
Schlagworte
- Verbundbrücke (9)
- Verbunddübel (6)
- Brückenbau (5)
- Autobahnbrücke (4)
- Brücke (3)
- Deutschland (3)
- Geschichte (3)
- Baustoff (2)
- Bauweise (2)
- Bewertung (2)
Institut
At the University of Applied Sciences Potsdam, students are introduced to working with built structures in the field of practical building analysis in the master's degree in civil engineering. The basis for the existing analysis is the geometry, materials used and the structure. New structural calculations are required for modifications or extensions. The students are taught which non-destructive testing methods can be used to determine the material properties of the building fabric. In addition, it is presented how the teaching is structured and using examples that show that teaching can be designed to be very practice-relevant.
This paper introduces (both formally and technically) a new concept: a hybrid steel–concrete cross section. The definition is based on the shear force transmission mechanism and it assumes the existence of a new type of shear connections, i.e. composite dowels. The hybrid cross-section is a generalization of composite steel-and-reinforced concrete cross sections and it is defined by a new way of dimensioning for vertical shear. The hybrid cross section concept is based on a specific approach to the lever arm of internal forces and an assumption that the local shear transfer mechanism of composite dowels is different than in the case of classic welded studs. The concept makes it possible to show by design calculations that the shear force is transferred through jointly the concrete part and the steel part. It is worth emphasizing that the proposed concept is a response to the new opportunities provided to engineers by composite dowels and to the fact that the bridge structures designed nowadays are different from the ones designed previously. The concept enables the design of completely new types of composite steel–concrete beams. The presented theoretical analyses verified by means of FEM show how the change of the shear connection level influences the division of the shear force in the cross section. This is included in the design concept through the internal lever arm of the hybrid section. The proposed concept has been shown to be internally consistent and complete.
Vor der industriellen Produktion von Stahlträgern und Brettschichtholz boten Zahnbalken eine Möglichkeit große Auflagerabstände im Hoch- und Brückenbau zu überspannen. Verzahnte Balken sind aus heutiger Sicht als nachgiebig zusammengesetzte Biegeträger zu betrachten. Dabei wirken die handwerklich hergestellten Zahnverbindungen in gleicher Weise wie zum Beispiel Dübel besonderer Bauart. Der zur statischen Nachweisführung benötigte Verschiebungsmodul ist in der aktuell gültigen Holzbau-Bemessungsnorm DIN EN 1995–1–1:2010 nicht ausgewiesen. Somit ist es zurzeit nur durch eine versuchstechnische Ermittlung des Verschiebungsmoduls für die jeweilige Zahngeometrie möglich, statische Nachweise durchzuführen.
Die Fußgängerbrücke am Stern-Center in Potsdam wurde vor sieben Jahren in Betrieb genommen. Seitdem werden sowohl von der Brückenverwaltung als auch von den Nutzern deutlich spürbare Schwingungen beim überqueren der Brücke festgestellt, die Anlaß zu Beunruhigungen geben.
Ziel der durchgeführten Untersuchungen war es, das Schwingungsverhalten und die Schwingungsursachen der Schrägseilbrücke anhand von Messungen zu identifizieren und ein geeignetes FE-Rechenmodell zu entwickeln, das die dynamischen Wirkungen hinreichend genau erfaßt.
Roebling became acquainted with Navier's theory at the Berlin Bauakademie in 1824/25. During his road planning work in Westphalia, he developed several suspension bridge projects in 1828. Roebling's travels along the Rhein and Ruhr in the winter of 1828 were connected with these projects. Roebling supplemented his notes on Dietlein's bridge-building lectures at the Berlin Bauakademie with excerpts from newer literature on suspension bridges. Under the title "Remarks on Bridge Construction" he discussed the results of his studies. Four known bridge projects can be distinguished. Two are only elaborated as an idea, in one case the project is only known by official letters. Only in the case of the Freienohl Bridge is there an exact description of the project. None of them have been brought to realization. Security considerations of the Berlin Oberbaudeputation probably led to the decision not to execute Roebling's Finnentrop project. This decision ought to be understood within the context of a bridge collapse in Nienburg /Saale in December 1825. When Roebling immigrated to the United States, he used his knowledge in construction methods and experiences with an experimental approach. For this reason, it is interesting to compare the early German projects with his first American bridges. While Roebling's first canal aqueducts combined suspension bridges with trusses, the Niagara Bridge marks a radical step forward to another dimension and to a new approach that emphasized thinking in terms of "systems". Interestingly, he also consistently maintained his construction principle for attaining stability by using rigid, wrapped main cables, inclined stays and wooden trusswork. Although he later used wrought iron profiles, he continued to use wooden constructions in his basic plans for a long time. There is no evidence that he made any contribution to the theories of trusses in a manner comparable with Whipple, Culmann, Gerber or others. Roebling's special talent lay in his constructive gifts.
Die Ende des 16. Jahrhunderts errichtete Nürnberger Fleischbrücke gilt als die bedeutendste Brücke der Spätrenaissance in Deutschland. Nach der Zerstörung des zweibogigen Vorgängerbaus durch ein Hochwasser im Frühjahr 1595 sollte die neue Brücke ohne Mittelpfeiler errichtet werden; wegen der angrenzenden Bebauung durfte sie jedoch nur sehr flach gewölbt sein, zudem stand zur Aufnahme des Bogenschubs nur ein wenig verlässlicher Baugrund zur Verfügung. Als Antwort auf diese Herausforderungen entwickelten die Nürnberger Baumeister ein Ausnahme-Bauwerk, dessen äußerst flacher Bogen die Spannweiten und Pfeilverhältnisse sämtlicher vergleichbarer Bauten im deutschsprachigen Raum weit übertraf, und das sich zudem durch ungewöhnliche Lösungen für den Steinverband und die Pfahlgründung auszeichnete. Im Sommer 1598 konnte es in der Rekordzeit von nur neun Wochen errichtet werden. Entworfen im Zeichen einer noch “unwissenschaftlichen” Bautechnik, hat sich die Fleischbrücke über die Jahrhunderte als Lehrstück robusten und nachhaltigen Konstruierens erwiesen.
Planung, konstruktive Durchbildung und Realisierung waren Ausdruck und Resultat einer hoch entwickelten reichsstädtischen Baukultur, Infrastruktur und Logistik. Ein Brückenwettbewerb wurde ausgelobt, in iterativer Optimierung allmählich die endgültige Lösung entwickelt. Ein umfangreicher Fundus bauzeitlicher Archivalien lässt die Strukturfindungsprozesse noch heute recht genau nachvollziehen. Entwurf und Konstruktion der Fleischbrücke gehören zu den bestdokumentierten Planungsprozessen eines Brückenbauwerks der frühen Neuzeit. Der Beitrag geht dem nach, was von den ersten Überlegungen bis zur Vollendung dieses Wahrzeichens der Ingenieurbaukunst gedacht, geplant, verworfen und letztlich realisiert wurde.
Location recommendation (LR) or rather location-based recommender systems (LBRS) are an integral part of modern location-based services (LBS). Most LR algorithms only focus on location-specific attributes when calculating recommendations, while completely ignoring the urban structure surrounding the locations. (In this paper we refer to a geographic coordinate (latitude and longitude) as position. Locations and places in contrast refer to physical entities e.g. a restaurant, a bus stop or a lake). This paper demonstrates how the urban structure can be modelled in LR calculations by using data from OpenStreetMap (OSM) and the location data itself. Based on these datasets, we present two approaches to extend the LR process by (1) including the urban structure in direct proximity of the location (Proximity Indicators and Areal Descriptors) and by (2) not only looking for individual locations but location clusters (Similarity Clusters). Thereby we acknowledge the complexity of a location, which can not be perceived as a detached entity. A location is part of a given urban structure and we need to include the parameters of this structure in our algorithms. A prototypical implementation compares locations from four major German cities: Berlin, Hamburg, Munich and Cologne and thereby highlights the applicability of the underlying data structures derived from OSM and the location data itself. We conclude by outlining the potential of the presented approaches in the context of LR as well as their relevancy for urban planning and neighboring disciplines.
Autonomous vehicles (AVs) seem to be the next big step into the future of mobility solutions. Various research institutions in the automobile industry and academic sectors are striving to come out with the most futuristic concept. This paper focuses on the interaction between AVs and pedestrians. Furthermore, the paper aims to explore if complex communication needs can be signaled to pedestrians through motion behavior of the vehicle.
In order to learn how other road users feel surrounded by self-driving cars, participants were confronted with different drivability of a self-programmed vehicle during our evaluation. As the results show, the vehicle's motion behavior is able to evoke certain emotions, which in turn lead to rational decisions within the participants. This can be seen as a form of mutual communication.
The German Association for Water, Wastewater and Waste e.V. (DWA) has published a new standard for the dimensioning, construction, and operation of constructed wetlands for treatment of domestic and municipal wastewater. The changes to the standard are based on a wide range of experience gained in recent years in Germany and Europe. For the first time ever, the standard has been officially translated and published in English. This paper summarizes the new standard for secondary treatment of domestic wastewater with classical one-stage unsaturated vertical flow (VF) wetlands, VF wetlands with lava sand for treatment of wastewater from combined sewer systems, and actively aerated VF and horizontal flow (HF) flow wetlands. Two-stage unsaturated VF wetlands treating raw wastewater (French VF wetlands), are also included in the new standard. HF wetlands are no longer described in the standard for secondary treatment of domestic wastewater. This does not exclude their application. Existing HF wetland systems in Germany may continue to be operated so long as effluent parameters are met and proper operations and maintenance is ensured. This paper gives an overview of the new design standard, including key information on wastewater type and loading, as well as primary attributes of each wetland design.