Verbundbrücke Pöcking – Innovative VFT‐Träger mit Betondübeln

The new road bridge over the railway line next to Pöcking applied to a new construction method for composite bridges. The VFT®‐construction method, which has been established in Germany within the last years combined with concrete dowel technology, generated a new type of prefabricated composite girders. Concrete dowels, which are manufactured by special steel web cuts connect rolled steel profiles with pre‐cast concrete members. An increasing degree of standardisation and prefabrication enables the application with an economic use of resources and a high quality level. This article describes design and manufacturing aspects of the new bridge, which is already under traffic use.     

Erneuerung von Großbrücken im Zuge hoch belasteter Autobahnen – Randbedingungen und Lösungsansätze am Beispiel der Urselbach‐Talbrücke

Renewal of highly frequented large‐scale motorway bridges. The bridge over the Urselbach – edge conditions and solutions. The newly built bridge across the Urselbach, which has a total length of 332 m, is part of the Federal Highway A5 near Frankfurt. The construction is composed of two bridges, one for each carriageway. Each superstructure consists of two steel box girders. Over these steel box girders, and resting on their top flange, is a cast‐in‐place concrete slab that becomes a part of the roadway. For a future renewal of the concrete slab it is requested that eight traffic lanes still have to remain during reconstruction. As one superstructure is passed by maximum six traffic lanes, the other must still be partly passable during its renewal. That's why the concrete slab can be demolished partly and afterwards concreted if it's necessary. Therefore the composite construction offered many advantages. The form of composite construction of the bridge across the Urselbach results from the combined action of structural steel and a concrete deck slab, which has the function of a replaceable structural member under traffic use. This conception was achieved by a structural analysis taking the substantial influences into account and the arrangement of some additional structural parts. The found solution should give some ideas on the way to a technical guide‐line for dimensional and structural design of concrete bridges with replaceable deck slabs.     

Die Stahlverbundbrücke über die Müglitz im Zuge der Autobahn Dresden–Prag – Entwurf und Ausführung

The composite bridge across the Müglitz on the highway Dresden–Prag. Design and construction. The bridge across the Müglitz transfers the newly built Federal Highway A17 over the small town Dohna near by Dresden. The bridge has a total length of 310 m and crosses a railway, a state highway and the river Müglitz. The bridge dominates the townscape. Extensive design investigations were performed to find the technically and aesthetically right solution for the given situation. Chosen and built was a continuous girder bridge as a composite structure with a span sequence of 45 – 55 – 55 – 55 – 55 – 45 m. The construction is composed of two bridges, one for each carriageway. Each superstructure has two airtight steel box girders, which are in composition with the concrete deck slab. To give the bridge a differentiated view, the main girders are built with shallow but significant haunches and emphasized stiffening boxes in the bearing zones. In the design of the composite columns these criteria reappear in the widening of the column heads and the eight‐cornered cross‐sections. Special consideration was given to a simple fabrication and an unproblematic erection with as far as possible reduced welding at the site. The article covers the planning and the building of the bridge. In addition experiences made in building other bridges with airtight box girders are reported.     

Entwurf und Konstruktion der Egg‐Graben Brücke

Aufgrund der hohen Erhaltungskosten von Brücken gibt es mittlerweile unterschiedliche Ansätze, um die Dauerhaftigkeit zu erhöhen. Vorgespannte Brücken ohne Betonstahl stellen hierfür einen neuen Ansatz dar. Zur Erforschung des Tragverhaltens solcher Strukturen wurde ein Forschungsprojekt gestartet und Großversuche durchgeführt. Die Landesbaudirektion Salzburg war von dieser innovativen Idee überzeugt und hat deshalb die Technologie beim Bau der Egg‐Graben Brücke ausgeschrieben. Die Egg‐Graben Brücke ist eine im Grundriss gekrümmte Bogenbrücke mit einer Länge von 50 m. Nach einer Bauzeit von 18 Monaten erfolgte im November 2009 die Freigabe für den Verkehr. Der vorliegende Aufsatz beschreibt die Technologie, den Entwurf sowie die beim Bau der Brücke gesammelte Erfahrung. Design and Construction of the Egg‐Graben Bridge Due to the high maintenance costs of bridges, there are now various approaches to enhance the durability. Post tensioned bridges without steel reinforcement represent one of these approaches. To investigate the structural behaviour of such constructions, a research project was started and large‐scale tests were carried out. The government of the province of Salzburg could be convinced of this innovative technology and tendered out the method for the construction of the Egg‐Graben Bridge. For the arch bridge, which is curved in plan, the superstructure is prestressed without using further steel reinforcement. After a construction period of 18 months the bridge was opened to traffic in November 2009. The paper describes the technology, the design and the experience gained from the construction of the bridge.     

Schrägseilbrücke für Straßenbahn‐, Geh‐ und Radverkehr

Cable‐stayed bridge for tramway, pedestrians, and bike traffic. For the development of the new quarter “Parkstadt Schwabing” in den North of Munich, the transport connection is established by a new tramway, the line 23. Thereby, a new bridge construction became necessary for the crossing of the main circular roadway “Mittlerer Ring” at the Schenkendorfstraße. The extraordinary bridge structure in direct conjunction with the glass enclosure of the Petuel‐tunnel belongs to the most spectacular metropolitan crossing locations of Munich.     

Die neue Ruhrbrücke in Wetter – Eine Stahlverbundbrücke mit luftdicht verschweißten Kästen

Von Mai 2008 bis Dezember 2010 wurde in Wetter eine neue Ruhrbrücke gebaut. Die exponierte Lage des Bauwerkes im Ruhrtal mit der Nähe zur Stadt Wetter begründete entsprechende Ansprüche an eine ausgewogene Gestaltung. Im Rahmen der Vorplanung wurden unter Beteiligung eines Architekturbüros zunächst umfangreiche Studien zur Auswahl eines geeigneten Brückensystems entwickelt. Der weiteren Planung und der Bauausführung zugrunde gelegt wurde eine etwa 361 m lange Deckbrücke in Stahlverbundbauweise mit luftdicht verschweißten Stahlkästen, mit einer maximalen Stützweite von fast 84 m und einer etwa 9 m hohen Voute über dem Pfeiler am Ruhrufer. Die Voute wurde durch Druckstreben aufgelöst und die Konstruktion dadurch gegliedert. Im Bereich der durch eine senkrechte Strukturschalung gestalteten Pfeiler wurde der Brückenüberbau parallelgurtig ausgebildet. The new Ruhr Bridge in Wetter, Germany – An air‐proof welded steel box girders. From May 2008 to December 2010 a new bridge over the Ruhr River was built in Wetter in Germany. The exposed location of the bridge over the Ruhr valley close to the city of Wetter requires a deliberate designed structure. Within the preliminary plannings, comprehensive studies about reasonable bridge construction systems were carried out, supported by an architecture office. Planned and realised has been a 361 m long bridge with air‐proof welded steel box girders and a concrete deck. The maximum span is nearly 84 m and the inclined haunch above the pier is about 9 m high. The inclined haunch has been formed with two diagonal struts to dissolve the construction. In the area of the vertical structured piers outside the Ruhr the bridge superstructure has been constructed with parallel chords.     

Fuß‐ und Radwegbrücke aus Carbonbeton in Albstadt‐Ebingen

Pedestrian bridge made from carbon‐concrete in Albstadt‐Ebingen – First entirely carbon‐reinforced concrete bridge worldwide The bridge erected in Albstadt‐Ebingen in October 2015 is realized without any steel reinforcement or pre‐tensioning, making it the world's first entirely carbon‐reinforced concrete bicycle and pedestrian‐bridge. The trough section with material thicknesses of 70 mm (trough walls) and 90 mm (slab) respectively has been fabricated as monolithic pre‐cast element. With a span length of 15 m and a width of 3 m, the bridge‐deck requires no further coating and has a total weight of just 14 tons (approximately 310 kg/m2); this is about 50 % of comparable conventional reinforced concrete bridge‐decks. Besides material and weight savings, an exceptionally long service life with minimal maintenance can be expected, as the steel corrosion that is typical in reinforced concrete structures can be entirely avoided. Since the use of carbon‐reinforced concrete (carbon concrete) is not yet approved in Germany, the client had to obtain approval based on individual cases (ZiE).     

Großversuch WILD‐Brücke – versuchsgestützte Bemessung einer UHPC‐Bogenbrücke

Full‐Scale Experiment Bridge WILD – Design of an UHPC Arch Bridge based on Experiments The outstanding durability of UHPC makes this material predestined for the construction of bridges. In Austria UHPC is introduced into the practice of road bridges through the realisation of the bridge WILD. The cross section of the arch, which spans 70 m, is just 6 cm thick and doesn't contain any passive reinforcement. The design is based on international recommendations on the one hand and on specific experiments on the other hand. This paper deals with the evaluation of two full‐scale laboratory tests. The setup is configured for getting a broad field of results as it is necessary for approval tests. In this way, all critical design states, which are also determined by calculation, are investigated experimentally. Furthermore, the experiments cover secondary effects, which don't have any verification through practical experience but can clearly be seen in FE‐results. The test results are carefully interpreted and explained by the use of simple mechanical models. The final examination of the results is figured out by means of comparison between calculation and experiment.     

Neubau der ÖBB‐Donaubrücke Tulln – ein innovatives Brückentragwerk

104 Jahre nach ihrer Erbauung wurde die Eisenbahnbrücke der Österreichischen Bundesbahnen (ÖBB) über die Donau in Tulln einer Generalsanierung unterzogen. Als Tragsystem der neuen Brücke wurde eine Fachwerkverbundkonstruktion mit untenliegender Fahrbahn gewählt. Nach nur 16 Monaten Bauzeit konnte mit der Inbetriebnahme im Oktober 2009 ein Stück europäische Brückenbaugeschichte geschrieben werden. Für die Demontage der bestehenden Tragwerke und die Montage des neuen Tragwerks inklusive der Ausrüstung für den Bahnbetrieb stand eine 7‐monatige Streckensperre zur Verfügung. Die Herstellung des Ersatzneubaus des 440 m langen Brückentragwerks unter möglichst geringer Beeinträchtigung des Straßen‐, Bahn‐ und Schiffsverkehrs stellte höchste Anforderungen an den Bauherrn, die Planer und die ARGE Donaubrücke Tulln. Errection of the ÖBB‐Donaubrücke Tulln – an innovative bridge construction. 104 years after being built, the railway bridge of the Österreichischen Bundesbahnen (ÖBB) across the Danube at Tulln, Austria, has been completely refurbished. The new bridge is based on a composite over‐deck truss construction. After a construction time of only 16 months, commissioning in October 2009 was the last step in a project that will make European bridge construction history. For the dismantling of the existing supporting structure and the assembly of the new one incl. the railway facilities, the railway line was blocked for 7 months. Replacing the 400‐m long supporting structure while keeping the effects on road, rail and shipping traffic to the lowest possible level put highest demands on owner, planners and ARGE Donaubrücke Tulln.     

Ganzfertigteile bei der Verbundfahrbahnplatte der Bahretalbrücke – Eine Revision nach Ausführung und baubegleitender messtechnischer Überwachung

Fertigteilbauweisen für die Herstellung der Fahrbahnplatten von Verbundbrücken konnten sich bei kleineren Brücken bereits durchsetzen. Verschiedene Bautypen wurden entwickelt: die VFT‐Bauweise, die Halbfertigteilbauweise, die Ganzfertigteilbauweise. Im Großbrückenbau ist die Anwendung, zumindest in Deutschland, bisher auf einzelne Fälle beschränkt geblieben und eine abgeschlossene Stufe der Entwicklung noch nicht erreicht. Die Ganzfertigteilbauweise, wie sie bei der Bahretalbrücke eingesetzt wurde, stellt eine Möglichkeit dar, die Vorteile der deutlich schnelleren Herstellung der Fahrbahnplatte im Großbrückenverbundbau effektiv zu realisieren. Besonderes Augenmerk ist bei der Bemessung und Konstruktion auf die Rissproblematik zu legen. Die hier aufgetretenen Rissbildungen begründen sich durch die unterschiedlichen Materialeigenschaften und Herstellungszeitpunkte der Fertigteile und der Ortbetonergänzungen. Mit Hilfe des baubegleitenden Messprogramms für die Bahretalbrücke konnten die Rissbildungen sowie insbesondere die Spannungen in den Anschlussbewehrungen der Fertigteile gut nachvollzogen werden. Letztere liegen aufgrund des “Sammelrisseffektes” deutlich über den Spannungen der Ortbetonbewehrung und können nicht einfach am Zustand II‐Querschnitt berechnet werden. Zusammenfassend kann für die Bahretalbrücke eine gute Beurteilung der Bauweise gegeben werden. Prefabricated elements for the floor system of Bahretalbridge. The construction of floor systems of composite bridges, using prefabricated elements in concrete, could already achieve acceptance for smaller bridges. Different types were developed: VFT‐types, semi‐precast construction, precast construction. So far there are only a few cases of prefabricated elements in concrete for bigger bridges in Germany. Using the precast construction presents a possibility to produce floor systems faster and more effective, as done with the Bahretalbridge. Special attention is to be turned to the calculation and construction of the crack formations. The crack formations seen in this particular construction happened because of the different material property and the production time of the prefabricated elements as well as the addition of floor systems. During the construction progress several measurements helped to understand the appearance of the crack formations. The stresses of the reinforcement between prefabricated elements and the in‐situ concrete are much higher due to the effect of accumulated cracks. Summarizing the construction of the Bahretalbridge was done in a decent way and deserves a positive evaluation.     

Schlanke Fußgängerbrücke aus Textilbeton

In Albstadt‐Lautlingen wurde eine ältere Fußgängerbrücke aus Stahlbeton durch eine elegante Brücke aus Textilbeton ersetzt. Durch die Kombination von textilbewehrtem Beton mit einer Vorspannung ohne Verbund ließ sich eine für Betontragwerke außergewöhnliche Schlankheit erzielen. Die 97 m lange Brücke über die Bundesstraße B 463 besteht aus sechs Fertigteilen, die bei einer Elementlänge von 17,2 m eine Bauhöhe von 43 cm aufweisen. Im Beitrag werden Konstruktion, Bemessung und insbesondere das Schwingungsverhalten beschrieben. Die Untersuchungen zu den verwendeten Baustoffen sowie zum Tragverhalten und zur Dauerhaftigkeit finden sich in einem separaten Beitrag in diesem Heft. A Pedestrian Bridge Made of Textile Reinforced Concrete The pedestrian bridge over a state road in Albstadt, Germany, had to be torn down due to immense corrosion damages of the steel reinforcement and was replaced by a new bridge. The design of the new bridge allows a slender and durable construction with high demands on the concrete surface. The bridge with a total length of 97 m is subdivided in six prefabricated parts with a maximum element length of 17,2 m and a span of L_s = 15 m. The height of only 43 cm is possible by using the innovative composite material textile reinforced concrete. Thus, a slenderness of L_s/H = 35 and an extreme slender bridge construction is achieved. Due to the non‐corrosive textile reinforcement a very small concrete cover is possible and, thus, webs and cantilever arms can be designed very thin. The paper describes the construction, design and dynamic behaviour. A report on materials, load bearing behaviour and on the durability is available as a separate paper in this issue.     

Die Geh‐ und Radwegbrücke Kehl – Strasbourg

The Pedestrian and Cycle Bridge Kehl – Strasbourg. The Rhine bridge between Kehl and Strasbourg is the new regional landmark and linking element of the International Gardening Show. The approach to unifying different functions and an architectural endeavour lead to a unique structural system. Two separate decks address the different situations on the river banks and, linked by a platform, form a balcony above the Rhine at midspan. The main bridge is a cable‐stayed structure with a steel pylon and a steel‐concrete composite deck. The approach bridges are continuous girders on steel columns. Both pile and flat foundations are featured in the design. The article describes the structural concept and design, outlines the erection procedure and discusses aspects of the dynamic behaviour of the bridge.     

Die Wupper‐Talbrücke Oehde – eine moderne Verbundbrücke

The Wupper River valley bridge – a state‐of‐the‐art composite bridge. The German motorway Autobahn A 1 is one of the nation's most important and frequently traveled highways, connecting the country's northern and southern regions. The road currently has two lanes in each direction, which do not provide enough capacity to carry the traffic volume without daily traffic jams and heavy delays. Therefore, the federal government and the Northrhine‐Westfalia Department of Transportation decided to ease the situation by adding one lane in each direction. This total of 6 lanes fits into the master plan of widening major highways around the Ruhr River region. North of Cologne, the Autobahn A 1 crosses mountainous terrain, so several bridges with total lengths between 240 and 420 meters have had to be widened, replaced, or, most commonly, supplemented by a new bridge. Such supplementation was used on the Wupper River Valley Bridge, called Oehde, close to the city of Wuppertal. The bridge illustrates an example of modern composite bridges adopting new methods in construction and design, and also marks an outstanding example of current composite structures in Germany.     

Feldversuche mit dem Brückenklappverfahren

Field Tests with the Balanced Lift Method As a counterpart to the lowering arch construction method the “balanced lift method” for bridge girders is suggested. The bridge girders can be built in combination with the pier using climbing forms in a vertical position. Therefore, during the production no bending stresses are generated in the girders. Thus, the balanced lift method allows lower costs and a shorter construction time than the traditional balanced cantilever method. The span of the bridge girders is reduced by the compression struts or tension ties which results in substantial savings in construction materials compared to the balanced cantilever method for bridge construction. The proposed method will be especially advantageous for bridges with high piers. The range of the span length for the application of the balanced lift method ranges between 50 m and 250 m.     

Schädigung einer schlaff bewehrten Betonbrücke durch Verkehrsbelastung

Evaluation of Damage Due to Traffic on a Reinforced Concrete Bridge An investigation of the damage caused by road traffic on a reinforced concrete bridge was performed. Focus was given to damage induced by extra‐heavy vehicles. A damage model based on fatigue of reinforcement bars was employed. The stress cycles in the reinforcement bars were determined using measurements of the crack widths under traffic loading which were analysed using the rainflow method and Miner's rule. A monitoring system was mounted and used for seven weeks continuously to collect input data for the damage model. Computer software was developed to process the monitoring data in the sense of the damage model. The results indicate that a singular passage of an extraheavy vehicle over the investigated bridge causes damage equivalent to the damage caused by one day of average weekly traffic. The described method was developed and used for the first time in the described project.     

Die Orinoco‐Brücke in Ciudad Guayana/Venezuela – Doppel‐Schrägkabelbrücke mit Verbundüberbau für Straßen‐ und Eisenbahngüterverkehr

The Orinoco River Bridge at Ciudad Guayana / Venezuela – a twin cable‐stayed bridge with steel composite bridge deck for road plus heavy rail traffic. The Orinoco Bridge at Ciudad Guayana carries a single track railway and a 2 × 2 lane highway across the Orinoco. The river has with low water a width of 1 km and with high water a width of 2 km. The total bridge length of 3156 m is subdivided into – the 1320 m long south approach bridge – the 1200 m long twin cable‐stayed bridge – the 636 m long north approach bridge. The bridge deck is a steel composite box girder and was erected partly by launching and partly by free cantilevering erection. The bridge is founded on large diameter bore‐piles. The paper deals with the design, special aspects of the calculation and the construction.     

Hermann‐Liebmann‐Brücke in Leipzig – Herstellung mit Spannverbund‐Trägern in geteilter Bauweise

Hermann‐Liebmann Bridge in Leipzig – Construction method with Spannverbund‐Girder. The Hermann‐Liebmann bridge is a five‐span road bridge over railway tracks in the city centre of Leipzig. It is built as a prestressed double composite bridge. Taking into account the traffic on and under the bridge, the demolition of the existing bridge has got decisive influence on the conception of its replacement. Deck structures on both sides of the existing bridge were erected first and served as the platforms to remove the old steel construction, to supply the construction site, and to constantly keep open the bridge for pedestrian traffic. This way, the ambitious bridge project could be realized reducing restrictions for the railway traffic to a minimum.     

Bewertung einer alten genieteten Stahlbrücke – Die Bösebrücke in Berlin

Evaluation of an old riveted steel bridge – The Böse‐Bridge in Berlin, Germany. This report is about the recalculation of the Böse‐Bridge in Berlin which was built between 1912 and 1916. A special feature of this three‐bayed truss arch bridge is the nickel steel used in the main bay. Different models have been used to recalculate the main structure, the truss nodes and the carriageway slab. The static analysis is based on the semi‐probabilistic concept. As a result of this recalculation the construction was classified to have the bridge capacity 30‐30 according to DIN 1072. Finally, this report concludes by determining the remaining lifetime depending on the concept of the Wöhler curves.     

Neubau der Rethebrücke,Hamburg

Mit dem Neubau der Rethebrücke, die eine Spannweite von 104,2 m aufweist, entsteht im Hamburger Hafen eine von Europas größten Doppelklappbrücken für den Straßenverkehr und die größte Doppelklappbrücke Europas für den Bahnverkehr. Getrennte Querschnitte ermöglichen eine wirtschaftliche Dimensionierung der Brücken entsprechend der unterschiedlichen Belastungen aus Bahn‐ und Straßenverkehr. Die Ausmaße der Klappen resultieren in ebenso mächtigen Klappenpfeilern, welche mit einer Tiefe im Baugrund von 21,7 m im Tidebereich der Elbe besondere Verankerungsmaßnahmen erfordern. Das Tragwerk der Brücke wird je Brückenseite aus vier sich zur Brückenmitte hin verjüngenden Fachwerkträgern gebildet. Im geschlossenen Zustand der Brücke ermöglicht eine spezielle Fingerkonstruktion in Brückenmitte, die ohne eine mechanische Verriegelung auskommt, die Übertragung positiver Momente. The new Rethebridge, Hamburg, Germany. With the erecting of the Rethebridge, which has a span of 104.2 m, the port of Hamburg gets one of Europe's largest road bridges and Europe's largest railway bridge with two movable spans (bascule bridge). The superstructure is divided in two parts, one for railway and one for road traffic, thus allowing an economic construction for the different loads. The size of the movable spans results in huge piers (21.7 m deep in ground) standing in Elbe's tidal area needing special anchorage measurements. The bridge's structure is composed of four truss girders, every bridge side, tapering to the middle of the bridge. At closed position, a special finger construction in the middle of the bridge allows the transfer of positive moments without any mechanical locking system.     

Die Karolinenbrücke in Salzburg – Ungewöhnliche Verstärkung einer bestehenden dreifeldrigen Straßenbrücke

Exceptional strengthening of a highway bridge with three spans. This paper deals with the exceptional strengthening of a continuous plate girder bridge. The structure was completed in 1938 and has no composite action with the concrete deck. Due to increased traffic actions and unscheduled material properties (undersized yield stress) a strengthening of the structure was necessary. Because of economic and production limitations (limited weld ability) the common procedure of strengthening the upper and lower chord of the main girder was not possible. Therefore additional main girders are situated on the upper side of the bridge deck. First the different form of strengthening structures – analysed in a preliminary study – are presented. Finally the chosen structure in forms of two continuous arches in the plan of the main girders is represented. This article describes the design concept, the structural design and selected highlights of the fabrication and erection.