Kathodischer Korrosionsschutz von Stahl in Beton: Instandsetzung des Parkhauses “Am Gericht” in Frankfurt am Main

Cathodic Protection of Steel in Concrete Rehabilitation of the Multi Storey Car Park “Am Gericht” in ”Frankfurt am Main” Within the last decades, the rehabilitation reinforced concrete structures that are affected by chloride‐induced corrosion have become more and more important. In such cases, cathodic protection as an electrochemical rehabilitation method often is a reliable and cost effective procedure. The rehabilitation of the multi‐storey car park “Am Gericht” in Frankfurt am Main shows exemplarily the realization of this technique. The theory of cathodic protection will be explained as well as special details that have to be considered in practice. The data of early de‐polarization measurements show the actual conditions of the cp‐system and the protected object, respectively.     

Berechnung einer Kombinierten Pfahl‐Plattengründung am Beispiel des Hochhauses “Skyper” in Frankfurt/Main

Am Bespiel des Hochhauses “Skyper” wurden durch den Unterausschuss “Kombinierte Pfahl‐Platten‐ und Pfahlgruppengründungen” des DIN verschiedene Berechnungsverfahren zur Berechnung einer Kombinierten Pfahl‐Plattengründung angewendet. Die Ergebnisse werden verglichen und diskutiert, wobei sich für den vorliegenden Fall herausstellte, dass sowohl numerische Verfahren als auch vereinfachte Verfahren, die auf der Halbraumtheorie basieren, akzeptable Ergebnisse liefern. Für eine Auswahl der geotechnischen Berechnungsverfahren wurden Federmodelle für die Abbildung der Reaktion der Baugrundoberfläche und der Pfähle abgeleitet und mit Ansatz dieser Federmodelle die Fundamentplatte bemessen. Auf dieser Grundlage gibt der Unterausschuss eine Empfehlung zur Anwendung von Berechnungsverfahren. Calculation of a piled raft foundation as a case study for the high rise building “Skyper” in Frankfurt/Main. Various calculation methods were applied on the piled raft foundation of the high rise building ”Skyper“. The results are compared and discussed. Numerical methods as well as simplified methods based on the elastic half space theory lead in the actual case to reasonable results. With the derived subgrade reaction modulus and pile stiffness the raft reinforcement was computed. A recommendation for the application of numerical and simplified methods is given.     

Energetische Sanierung einer Kindertagesstätte in Plattenbauweise – Demonstrationsbauvorhaben “Plappersnut” in Wismar

Energy saving retrofitting of a prefabricated panel construction kinder‐garden – demonstration project “Plappersnut” in Wismar. The project “kindergarten Plappersnut” in Wismar focuses on cutting the energy consumption of the in 1972 build prefabricated plate construction down to one third by mainly 3 means: – improving the relation between building volume and outside surface by replacing the corridor building between the two main wings with a light membrane roof, covering the whole space, – eliminating energy loss through the building structure by coating the whole building with different isolation systems, – replacing all of the technical installation under the aspects of ecological energy supply and energy retrieving systems. The project was classed as a demonstration project of the EnSan‐Program, supported by the German Ministry for Economy and Technology.     

NordWestZentrum Frankfurt am Main – Teil 2: Erweiterungsneubauten

The NordWestZentrum in Frankfurt/Main – Part 2: new annexe. The NordWestZentrum was expanded once more in 2002–2004. As part of this project, the area previously occupied by a technical college was completely redeveloped, resulting in 430,000 m³ of enclosed space for new utilization. For the planning engineers, this construction project was a major challenge in terms of demolition, expert reports, modernization and safeguarding of the existing buildings as well as structural design for the new buildings with their special foundations, all under the motto “Bauen im Bestand und Bauen im Betrieb” which can be loosely translated as “construction within the existing buildings and construction during operations”.     

Der “Steg Süd” am Bahnhofsareal Remscheid

Der “Steg Süd” am Bahnhofsareal Remscheid ist der Dreh‐ und Angelpunkt im neugeschaffenen Einzelhandelszentrum am revitalisierten Bahnhofsareal in Remscheid. Das im Zuge der “Regionale 2006” geschaffene Brückenbauwerk bildet den gestalterischen Mittelpunkt des neuen Centers und schafft darüber hinaus Wegeverbindungen in verschiedenen räumlichen Ebenen zwischen Stadtteilen, Bauwerken und Verkehrsinfrastrukturen. Southern Pedestrian bridge at Remscheid Central Station. The southern pedestrian bridge at Remscheid Central Station is the heart of the new shopping centre, which was erected on the redeveloped Remscheid central station area. The bridge makes up the architectural face of the new centre and beyond that creates new connecting passages on different spatial levels between municipal areas, buildings and traffic facilities. The bridge is part of the project “Regionale 2006”.     

“Die Raupe” – eine bewegliche Brückenkonstruktion

Für einen Brückenwettbewerb in Wien wurde ein Konzept einer beweglichen Brücke in Form eines Fischbauchträgers entwickelt, das neben seiner strengen Funktionalität und der materiellen Effizienz über einen innovativen Hebemechanismus verfügt. Die Idee des Hebevorgangs basiert auf einer Verkürzung des Trägeruntergurts durch Seile und zwei zwischengeschalteten hydraulischen Zylindern. Die Anhebung der Brücke zur Freihaltung des geforderten Lichtraumprofils erfolgt asymmetrisch, was ein raupenähnliches Verkrümmen zur Folge hat. Des Weiteren wurde die Deckplatte dahingehend optimiert, dass unter Verwendung hochfester Stähle die große Verformung über das elastische Werkstoffverhalten aufgenommen und so auf wartungsintensive Gelenke verzichtet werden kann. Durch das gewählte statische System mit dem applizierten Hebemechanismus kann die Einleitung großer Horizontalkräfte in den Boden vermieden und dadurch die Kosten deutlich gesenkt werden. Das Konzept wurde für eine Spannweite von ca. 60 m entwickelt, kann jedoch auch für andere Spannweiten adaptiert und so vielerorts eingesetzt werden. “The Caterpillar” – A moving bridge structure. For a design competition for a bridge in Vienna, a concept for a moving bridge in the form of a lenticular girder was developed which, in addition to its strict functionality and material efficiency, features an innovative lifting mechanism. The lifting principle is based on shortening the lower chord of the girder with the help of cables and two intermediate hydraulic cylinders. In order to create the required clearance profile, the bridge is lifted asymmetrically, which results in a deformation of the shape which is reminiscent of a caterpillar. In addition, the upper deck was designed using hightensile steel so that the considerable deformation could be absorbed by the elasticity of the material, which means that maintenance‐intensive hinges could be omitted. This structural system with its lifting mechanism makes it possible to significantly lower costs as there are no large horizontal forces to be transferred to the ground. The concept was developed for a span of approx. 60 m but can also be adapted to spans of different sizes and is therefore suitable for many situations.     

“Produktionsverfahren im Stahlbau” – online – Lehrveranstaltung via Internet – ein Versuch

“Production processes in steel construction” – online. Teaching via internet – an attempt. At TU Darmstadt the course “Production Processes in Steel Construction” is offered for resident students and via internet since two years. This enables external students to participate without being personally in Darmstadt. This was possible without a great burden on the existing course and the lecturer. In this we see an enhancement of the traditional curriculum. In times of reduced budgets this allows to offer courses which might not be presented with a reduced staff. This might be the basis for an inter‐university network of lectures and courses that can be created and offered for the benefit of the students. This paper describes the specific features that had to be regarded for the development of the project in the World Wide Web. Results of the evaluation and of the examinations are also given.     

NordWestZentrum Frankfurt am Main – Teil 1: Umbaumaßnahmen und Ertüchtigungen

The NordWestZentrum in Frankfurt/Main – Part 1: rebuilding and repair measures. The NordWestZentrum is one of the largest mall and event centers in Germany. There are six bus and an underground line and additionally 3500 parking spaces. For the first time opened in the year 1968, the center was completely revitalized in the years 1986 to 1988 and converted to a modern experience world. With a further large construction measure in the years 2002 to 2004 the sales area extended again considerably. In connection with the measures between 2002 and 2004 also a part of the existing state had to be rebuilt and repaired, this under continued service conditions. Handling the existing built volumes and the integration of new, efficient carrying constructions into the existing state represented a special challenge for the structural design.     

The Houston Growth Coalition In “Boom” and “Bust”

ABSTRACT: Although growth machine theory emphasizes the coalition's tactics and organization, it neglects adjustment to changing economic conditions. This article explores the changes in the strategy and organization of Houston's growth coalition during the peak growth of the 1970s and the decline of the 1980s. During the boom, the coalition focused not on additional growth but on easing the city's infrastructure problems. The coalition underwent several major changes during decline as it struggled to compete aggressively with other cities for various enterprises and to devise strategies for diversifying the economy. A growth coalition has the opportunity to establish the economic basis for future growth when the city's dominant industries reach maturity and decline.