Cable-Stayed With Steel Deck

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


	The first cable-stayed bridges of modern time (Strösund Bridge in Sweden and North Bridge in Düsseldorf) were designed with steel decks. Currently a steel deck is chosen where light weight is important due to poor soil conditions or where an unusually long span is required.



	H36. Overall view.

SCHILLERSTEG AT STUTTGART
(1961)

Pedestrian Bridge across the Schillerstrasse.
The girder forms a Y in plan, with the straight main spans of 68.6 meters across the street, dividing into the curved arms of the Y at the far end.
The girder is a flat hollow steel box with a depth of only 500 millimeters.
First bridge with parallel wire cables with a corrosion protection by PE-pipes and cement grout.


	H37. View from underneath.

Design.

Ref: Leonhardt, F. and Andrä, W.: “Fussgängersteg über die Schillerstrasse in Stuttgart (Pedestrian Bridge across the Schillerstrasse in Stuttgart),” Die Bautechnik 39 (1962), pp 110-116.



	H38. The model shows the North Bridge (Theodor-Heuss-Bridge) in the background, the Oberkassel Bridge, and the Knie Bridge in the foreground.

DÜSSELDORF RHINE BRIDGE FAMILY
(1953-75)

The family of three cable-stayed bridges across the Rhine River at Düsseldorf has, due to the similarity of the cable arrangements, a homogeneous aesthetic appearance in spite of the fact that one is symmetric and two are unsymmetric, and that they have 4, 2 and 1 towers. Their construction spanned more than two decades.

NORTH BRIDGE
(1953-56)



	H39. Overall view.


	Four-lane highway bridge with spans of 108-260-108 meters. First cable-stayed bridge in Germany. 26.6-meter wide bridge deck formed by two 1.75-meter wide, 2.6-meter deep box girders and orthotropic plate. 40-meters high, single-cell towers without cross girder. Cables formed by 6 to 12 locked coil ropes 68 to 72 millimeters diameter. Erection of side spans on auxiliary piers and of main span by free cantilevering with floating cranes.

Static model testing.
General consulting to the authority.
Design (in collaboration).

References:

Beyer, E. and Tussing, F.: “Nordbrücke Düsseldorf (North-Bridge Düsseldorf),” Der Stahlbau 24 (1955), pp 25-33, 63-67, 79-88.

Leonhardt, F. and Zellner, W.: “Cable-Stayed Bridges, Report on Latest Developments,” Canadian Structural Engineering Conference Proceedings, 1970.

KNIE BRIDGE
(1965-69)

Six-lane highway bridge. Unsymmetric, one-handed arrangement of cables with spans of 47.15, 4 x 48.75, 319 meters.
Bridge deck with total width of 28.9 meters, formed by two 3.4-meter deep plate girders 21.5 meters apart and an orthotropic plate.
114-meters high, four-cell tower columns with T configuration and without cross girder.
Cables formed by 13 locked coil ropes, each 72 millimeters diameter, passing over saddles at the tower.
Erection of side spans on final and auxiliary piers, starting from the abutment. Erection of main span by free cantilevering with derrick, using auxiliary stay cable systems between anchor points of final cables, and a tempotaty horizontal bracing in order to guarantee aerodynamic stability of the 319-meter long cantilever.

Extensive wind-tunnel testing.
Tender design and tender documents (in collaboration).
Consulting during construction.

Ref: Leonhardt, F. Andrä, W., and Wintergerst, L.: “Entwurfsbearbeitung und Versuch (Design and Tests),” in Tamms-Beyer: Kniebrücke Düsseldorf. Beton-Verlag, Düsseldorf, 1970, pp 53-72.



	H40. Overall aerial view.


	H41. Towers from Oberkassel embankment.


	H42. View from underneath.


	H43. Detail of cable anchorage.

OBERKASSEL BRIDGE
(1970-76)

Four-lane street and two-track streetcar bridge, replacing an older truss girder bridge with insufficient width. The condition of not interrupting the traffic required a special static system and a complicated construction sequence. Unsymmetric one-handed arrangement of cables with spans of 5 x 51.55-257.75-70 meters. Cables in a single plane along center-line.
35-meter wide, 3.15-meter deep bridge deck, consisting of a three-cell box girder with inclined outer webs and an orthotropic plate.
100-meter high, one-cell tower has dimensions of 3.5 . . . 4.2 x 2.8 . . . 3.2 meters.
Cables formed of seven locked coil ropes of 78 and 92 diameter each, passing over saddles at the tower.
Erection 47.5 meters upstream from the final position on temporary piers, side spans on temporary and auxiliary piers, main span by free cantilevering with derrick.
After dismantling the old truss girder bridge and constructing the final and intermediate piers, the bridge was moved 47.5 meters downstream, and the temporary and intermediate piers were removed.
During moving, the bridge was supported only at both abutments, the tower and the pier at the Düsseldorf embankment. In order to achieve this, the bridge was balanced with the cables in such a way that the reaction forces at the intermediate piers on the Oberkassel side were virtually zero.
Total weight to be moved was 12,700 tons, 10,300 of which were at the tower.
Moving was done on Neopot-Teflon sliding bearings, the friction coefficient of which had been determined experimentally.
The bridge was pulled only at the tower and at the Düsseldorf embankment pier using hydraulic center hole jacks; brakes wer provided at the same piers.

General consulting to Authority.

References:

Beyer, E., Volke, E., Grassl, H., von Gottsetin, F., Andrä, W., and Wintergerst, L.: “Die Oberkasseler Rheinbrücke und der geplante Querverschub (The Oberkassel Rhine Bridge and the Planned Lateral Shifting).” In Beyer, E. and Lange, K.: Verkehrsbauten (Structures for Traffic). Düsseldorf: Betonberlag 1974, pp 77-95.

Beyer, E., Volke, E., Grassl, H., von Gottsetin, F. and Ramberger, G.: “Neubau und Querverschub der Rheinbrücke Düsseldorf-Oberkassel (Construction and Lateral Shifting of the Rhine Bridge Düsseldorf-Oberkassel),” Der Stahlbau 46 (1977), pp 65-80, 113-120, 148-154, 176-188.

Firmage, D. A.: “The Lateral Shifting of the 2000-foot Oberkassel Bridge,” Civil Engineering - ASCE, May 1977, pp 67-70.


	H44. Plan of construction phases. Above: Construction of new bridge 47.5 meters upstream of final position. Center: Dismantling of old bridge and building new foundations on old axis. Below: Lateral shifting and final position.


	H45. Shifting installations at tower. Left: Temporary pier. Center: Intermediate pier. Right: Final pier.


	H46. Overall view of finished bridge.


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	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