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Alexander Kierdorf 《Stahlbau》2011,80(3):198-204
Im Wettbewerb um den Bau der ersten Kölner Rheinbrücke erhielt der junge Berliner Ingenieur Johann Wilhelm Schwedler den Ersten Preis für einen Hängebrücken‐Entwurf, der auf einer Planung seines Bruders aufbaut und sich eng an die Vorgaben der Ausschreibung hielt. Da aber schnell klar wurde, dass die verlangte Hängebrücke mit Schifffahrtsöffnung den stetig wachsenden Anforderungen an eine Eisenbahnbrücke nicht genügen konnte, schuf Schwedler kurz darauf einen Alternativentwurf, bei dem er die Fahrbahn an abgestumpft linsenförmigen Trägern aufhing. Dieser Entwurf, der bisher unbekannt war und erst im Jahre 1900 publiziert wurde, steht in engstem Zusammenhang mit Schwedlers bahnbrechender, ebenfalls zunächst kaum wahrgenommenen Publikation der “Theorie der Brückenbalkensysteme” von 1851. In Köln entschied man sich 1853/54 für den Bau einer Gitterträgerbrücke nach dem Vorbild der Dirschauer Weichselbrücke. Als Schwedler Jahrzehnte später genau dort seinen letzten Großbau ausführen konnte, nahm er die Kölner Entwürfe auf; in statisch aktualisierter Form bildeten sie ein Dokument des Fortschritts im Brückenbau und ein gebautes Manifest zugunsten der theoretisch‐wissenschaftlich fundierten Ingenieurbaukunst, an deren Durchsetzung Schwedler maßgeblich beteiligt war. Of vision and genius – The forgotten alternative design by Johann Wilhelm Schwedler for the first Rhine Bridge at Cologne, Germany. The competition on the first Rhine crossing was won, with a suspension bridge construction, based on his brother's preparatory designs and closely following the rules, by young engineer Johann Wilhelm Schwedler from Berlin. But it soon became clear that the bridge, including an opening section, could not cope with the constantly rising demands of railway traffic, and Schwedler created an alternative design, consisting of lenticular trusses with a suspended track. This design, hidden for al long time and published only once in 1900, is closely linked with Schwedler's groundbreaking, but also first neglected publication on the “Theory of Bridge Truss Systems” in 1851. Some years later, a lattice truss bridge was built at Cologne, following the Weichsel bridge at Dirschau (1850–55). Decades later when Schwedler got the chance to build another large size bridge right there, he returned to the Cologne design of 1850. Structurally modernized, he made it a document to progress in bridge building and a manifesto for an Art of Engineering based on science and theory, the success of which was not to a small extent the work of Schwedler. 相似文献
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《Stahlbau》2018,87(2):136-148
An integrated steel composite floor slab system. Within the scope of the AiF research project 18658 N [1] the integrated composite floor slab system InaDeck [2] is developed further concerning the practical application. The floor slab system is characterized by large spans and integrated building services. In order to lead this integrated floor slab to practical suitability on the one hand the floor slab elements are optimized with regard to their structural behaviour, their economic efficiency and their resource utilization, on the other hand the integration of the slab system into the overall supporting structure of the building are developed. The structural behaviour of the optimized floor slab elements is explored in experimental and theoretical investigations. Here, on the one hand the local mechanisms of the shear connectors in the region of web openings are examined on the other hand the effects of a combined lateral and longitudinal bending stress in the slab element are tested. Moreover, the vibration behaviour of the lightweight composite slab is analysed. The article summarized the essential results of the research project. 相似文献
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Aromatics: From Valuable Base Chemicals to Surplus Components? With the advent of the second stage of the European Auto Oil Programme in the year 2005, the aromatics content of gasoline has to be reduced significantly, which could lead to an oversupply of aromatics. The sources of aromatic hydrocarbons and their petrochemical use are described. Options for avoiding a surplus of aromatics are discussed, i.e., diminishing the production of aromatics and intensifying their conversion into valuable products. Finally, a novel catalytic process for hydrogenative ring opening of aromatics is introduced which allows the conversion of pyrolysis gasoline from naphtha steamcrackers into a high‐quality synthetic steamcracker feedstock composed of ethane, propane, and n‐butane. There are two process variants, namely the direct conversion of aromatics on bifunctional zeolites or a two‐stage process comprising a conventional ring hydrogenation to cycloalkanes followed by ring opening of the latter on acidic zeolites. 相似文献
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Josef Hegger Martin Claßen Peter Schaumann Jrg Sothmann Markus Feldmann Bernd Dring 《Stahlbau》2013,82(1):11-17
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Bjrn Helfers 《Bautechnik》2019,96(8):595-600
Reconnecting the historical harbor Bad Karlshafen to the river Weser – Expedient lock planning Bad Karlshafen is a beautiful planned town at the northern tip of Hesse. In 1699 the founder, Earl Carl , ordered to drain the swampy area at the Diemel Estuary where it joined the Weser for creating a baroque town around the basin. The new town in the basin was designed to impress the crews of incoming ships with its marvelous architecture. For that the Earl used state‐of‐the‐art technology at the time which demonstrated his mastery over the landscape and nature. At present the historic lock doesn't operate and the bridge over the former harbor entrance is now a road embankment. This was changed and the historical harbor is reconnected to the river Weser. 相似文献
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