Das Sturmflutsperrwerk Rotterdam - eine Gemeinschaftsleistung des Ingenieurbaus in den Niederlanden

Mit dem Sturmflutsperrwerk Rotterdam wird das letzte Glied in der Kette des berühmten Delta-Planes geschlossen. Durch das Sperrwerkes sollen landseitig die maximalen Wasserstände verringert werden, z. B. im Bereich der Stadt Rotterdam um 1,6 m. Dadurch entfällt die Notwendigkeit, die vorhandenen Deiche in Rotterdam und in seiner Umgebung zu erhöhen. Durch das Bauwerk, das in Normalsituation einen Schiffsweg von 360 m Breite offen hält, wird voraussichtlich alle fünf bis zehn Jahre bei extremen Sturmfluten die Schiffsroute zum Welthafen Rotterdams durch zwei große Stahltore verschlossen werden. Das Bauwerk wurde 1997 fertiggestellt. Es ist ohne Vorbild, daher mußten die Entwurfs- und die Ausführungsingenieure vielfach neue Wege gehen. Nachdem in [1] der Weg von der ersten Idee zum Ausführungsentwurf dargestellt worden ist, wird jetzt über Probleme des Entwurfes und der Ausführung sowie ihre Lösung berichtet

A review of methods for constrained eigenvalue problems

Numerous studies are concerned with vibrations or buckling of constrained systems realising that complex systems can be analysed when starting from unconstrained or known problems. Over the years various constrained eigenvalue formulations have been published and put into practical use. The most important ones are the Lagrangian multiplier method (modal synthesis method or component modes synthesis method), the receptance method and the modal constraint method. In this paper the similarities and merits of the various methods are discussed. It is striking that so far the similarities of the various constrained eigenvalue expressions have not been reported nor has the similarity of the eigenvalue expressions of these methods with Weinstein's determinant for intermediate problems of the first type been noticed. The eigenvalue formulations of the Lagrangian multiplier method and that of the receptance appear to be similar to Weinstein's determinant for intermediate problems of the first type. The modal constraint method is based on an extension of Weinstein’s method for intermediate problems of the first type and offers some significant advantages, i.e. the resulting eigenvalue formulation of the modal constraint method has a standard form in contrast with that of the other mentioned methods in that they have the known and unknown eigenvalues in the denominator of the eigenvalue formulations. Further, zero modal displacements, persistent and multiple eigenvalues do require special attention using these methods whereas this is not the case for the modal constraint method. Based on the similarities of the various constrained eigenvalue expressions a number of interesting conclusions are drawn

Elastic web crippling of thin-walled cold formed steel members

In this paper, first two different analytical web crippling stiffness models are described, namely a beam-on-elastic-foundation model and an energy model. Then a description is given of the finite element model, which was used to check the accuracy of these models. These finite element simulations have been validated against experimental results. Subsequently the parameter study is described, which was carried out to compare the results of the beam-on-elastic foundation model and the energy model with the results of finite element simulations. Based on these results the analytical models have been optimized by adding empirical correction factors. Finally conclusions and recommendations for further research are given

Automated Generation of Structural Solutions based on Spatial Designs to serve as a Support Tool in early Stages of the Design Process

Design processes are sets of complex, iterative and multidisciplinary procedures applied to achieve particular solutions. To aid in the understanding of design processes and to support the involved actors, a Research Engine (RE) is being developed. The RE is a set of computational processes which work together, in a cyclic manner, to simulate the interaction between spatial designs instances and structural solutions within a design process. This paper presents the first developed phase of the RE; in which the Spatial Design is transformed into a Structural Solution. In other words, given an orthogonal geometry (Spatial Design) this process generates a structure, performs a structural analysis and, consequently, provides an indication of its structural behavior. In early stages of the design process, this phase of the RE could help designers to (1) devise different structural solutions for a given spatial design; (2) to obtain an indication of the spatial consequences of the structural solution; and (3) to predict the structural behavior of the generated solution. Examples illustrate the process in practice during this first phase of the RE, and also show its capabilities in assisting in the integration between spatial and structural considerations within the design process

Duurzaam bouwen op bestaande funderingen

In de jaren vijftig en zestig zijn in Nederland ruim 250.000 gestapelde woningen gebouwd. Bijna veertig jaar later voldoen deze flatgebouwen niet meer aan de huidige eisen: het vervangen van deze woningvoorraad vormt het komende decennium een belangrijke bouwopgave. In het kader van een afstudeeropdracht aan de Faculteit Bouwkunde van de TU Eindhoven zijn de mogelijkheden onderzocht voor vervangende nieuwbouw op bestaande funderingen.Het aspect 'duurzaam bouwen' speelde daarin een belangrijke afweging. Er is een methode ontwikkeld om ontwerpvarianten op duurzaamheid te kunnen beoordelen