Steel Continuous Girder Bridges

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	*National Information Service for Earthquake Engineering* *University of California, Berkeley*

Due to a steel shortage in Germany during and after World War II, material saving designs, although labor consuming, were a requirement of the time. The answer of German engineers to this requirement was the development of the orthotropic deck.

As early as 1934, Professor Leonhardt made tests on such decks and developed methods for their analysis.

The orthotropic deck reduced the weight of continuous beams considerably and permitted spans and slenderness ratios unknown until then.

The following are some outstanding examples of continuous girder bridge design by Leonhardt, Andrä and Partners:



	H3. Overall View: In the background, Gothic Cathedral, height of towers 156 meters.

RHINE BRIDGE, COLOGNE-DEUTZ
(1946-47)

Combined road-streetcar bridge.
First slender steel box girder replacing a chain suspension bridge destroyed during World War II.
Spans: 132.1-184.5-120.7 meters, girder depth at piers 7.8 meters and at center of midspan 3.3 meters, corresponding to slenderness ratios of 1:24 and 1:56.
Orthotropic deck with reinforced concrete wearing layer.
Erection in large elements with heavy lifting equipment.
For subsequent widening of this bridge see Slides H27-29.

Final design (in collaboration).

Ref: Leonhardt, F.: “Die neue Strassenbrücke über den Rhein von Köln nach Deutz (The New Road Bridge over the Rhine from Cologne to Deutz),” Die Bautechnik 26 (1949), pp 193-199, 269-275, 308-315, and 332-338.



	H4. Overall view of the larger main bridge.

RHINE BRIDGE AT SCHIERSTEIN
(1958)

Six-lane highway bridge over two branches of the Rhine River, total length 1281.6 meters.
Main bridges with spans of 70-170-70 meters and 85-205-85 meters as steel girders with orthrotropic plates, approach and intermediate spans as composite girders.
Girder depth of main bridges 6.5/7.9 meters at piers and 3.7/4.2 meters at the center of the main span, corresponding to slenderness ratios of 1:26 and 1:46, respectively.
First application of Neoprene pot bearings with capacities up to 2500 tons in a long span bridge.
Erection of side spans on auxiliary piers and of main spans by free cantilevering.

Tender design and tender documents.

Ref: Weitz, F. R.: “Entwicklungstendenzen des Stahlbrückenbaus am Beispiel der Rheinbrücke Wiesbaden-Schierstein. (Trends in the Development of the Design and Construction of Steel Bridges exemplified by the Rhine Bridge Wiesbaden-Schierstein).” Der Stahlbau 35 (1996), pp 289-301, 357-364.



	H5. Overall view.

RHINE BRIDGE AT BONN-SOUTH
(1968-72)

Six-lane highway and double-track streetcar bridge, total width 39.7 meters.
Main span 230 meters, side spans 125 meters.
Cross-section consisting of two box girders and an orthotropic plate.
Depth 9 meters at piers and 4.2 meters at the center of the main span, corresponding to slenderness ratios of 1:26 and 1:55, respectively.
Inner webs inclined in order to fulfill safety requirements for radar-navigation of ships.

Selected proposal for a design and construction competition (in collaboration).

Ref: Lange, K.: “Modern Stahlbrückenbau (Design and Construction of Modern Steel Bridges).” Reprint of a lecture given at the University of Karlsruhe on November 15, 1972.



	H6. Erection.


	H7. Overall view of finished bridges.

MOSEL VALLEY VIADUCT AT WINNINGEN
(1968-72)

Six-lane Autobahn Bridge with spans of 156.8-218.2-170.5-146.1-133.9-109.6 meters, corresponding to a total length of 935.1 meters.
Maximum height above ground 133 meters.
Total deck width 30.5 meters, supported by a 10.8-meter wide box girder and inclined struts. Girder with variable depth, maximum 8.5 meters corresponding to slenderness ratios of 1:25.7.
Construction of piers with climbing formwork. Construction of superstructure from both sides on final and auxiliary piers by free cantilevering.

Preliminary design, tender design and tender documents, checking of final calculations and drawings.

Ref: Zellner, W.: “Long Span Box Girder Bridge across the Mosel Valley, West Germany,” Preprint MTL-61 to ASCE/EIC/RTAC Joint Transportation Engineering Meeting, Montreal, July 15-19, 1974.


	H8. View from the vineyards of the Mosel Valley.

KÖNIG-KARL-BRIDGE ACROSS THE NECKAR AT STUTTGART
(1970-76)



	H9. Overall view.


	Six-lane road and two-track streetcar bridge with a total width between 45.5 and 53.5 meters and spans of 37.0-50.8-50.8-46.1 meters replacing an old arch bridge. Superstructure with 8 to 9 cell box girder, depth 1.82 meters, corresponding to a slenderness ratio of 1:27.9, converting the bridge into possibly the widest and longest continuous steel box slab. Due to nearby mineral springs, the piers of the much smaller former bridge could not be widened. Therefore, the construction of the new bridge and dismantling of the old was done in steps in the transverse direction, maintaining at least the traffic width of the old bridge.

Tender design and preparation of tender documents.

Ref: Müller, Th. and Meinsma, H.: “Der Neubau der König-Karl-Bücke über den Neckar in Stuttgart (The Reconstruction of the König-Karl-Bridge across the Neckar at Stuttgart).” Acier-Stahl-Steel 3/1975, pp 92-97.



	H10. Layout.


	H11. Overall view.

NECKAR VALLEY VIADUCT AT WEITINGEN
(1973-78)

Six-lane Autobahn Bridge with spans of 234-134-134-134-264 meters, corresponding to a total length of 900 meters. Maximum height above ground 124 meters.
Due to poor foundation conditions in the slopes of the valley, the side spans needed to be extremely long and are, therefore, supported by an inverted stay-cable system of steel struts and locked coil ropes with diameters of 105 and 120 mm.
Total deck width 31.5 meters, supported by a 10.0-meter wide, 6.0-meter deep box girder and inclined struts.
The two slender octagonal columns are in the valley, and the framed double columns at the slopes take the wind loads.
Cantilevering construction of bridge deck from both sides on final and auxiliary piers.

Preliminary design, tender design and tender documents. Checking of final calculations and drawings.


	H12. Detail of Piers

References:

“Inverted Stayed-Girder Bridges Soil Problems,” Engineering News Record. November 23, 1978, pp 18-19.

“Cable-Stayed Bridge with Cables Below Deck Level in Germany,” Civil Engineering - ASCE, December 1978, p. 18.

Zellner, W.: “Schmuckstück am Neckar (Show-Piece across the Neckar).” Consulting 2, 1979, pp 20-22.

Wössner, K., Andrä, W., Kahman, R., Schumann, H. and Hommel, D.: “Die Neckartalbrücke Weitingen (The Bridge across the Neckar Valley at Weitingen),” Der Stahlbau 52 (1983), pp 65-77 and 113-124.

Godden, W. G.: “Construction,” Structural Engineering Slide Library, Volume 2, Slides G43-50, International Structural Slides, Berkeley, California, 1980. (Slides showing details and construction of Neckar Valley Bridge at Weitingen).



	H13. Artist’s rendering.

WERRA VALLEY BRIDGE AT HEDEMÜNDEN
(1983)

Combined six-lane Autobahn and double-track railway bridge for 250 kilometers per hour high speed railway.
Spans of 80-96-96-80-64 meters corresponding to a total length of 416 meters. Total width of highway 38.5 meters, distance between truss girders 16.5 meters. Autobahn deck above and railway deck below as orthotropic plates.
Up to 50 meters high piers of masonry and concrete filling, built in 1936 for a four lane Autobahn bridge, can also be used for the much heavier new bridge due to the improved bearing conditions.


	First-prize winner in a design competition.


	The University of California, Berkeley Copyright 1997, The Regents of the University of California. Structural Engineering Slide Library, W. G. Godden, Editor Set H: Structures of Leonhardt, Andrä and Partners


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