Bridge (8 1)

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Bridge Engineering (8)

SuperstructureCable-stayed Bridges

1. *Components of Cable-stayed bridges

1.1 (tensioned) inclined cables/stays;

1.2 orthotropic deck;

1.3 (stiffened) continuous girders; and

1.4 towers.2. *Stays

2.1 Materials: high-strength steels

2.2 Types of stays:

2.2.1 parallel steel bars;2.2.2 steel wire cables: parallel wire strand (PWS),

parallel wire cable (PWC);

2.2.3 stranded wired cables: parallel stranded wired

cables, locked coil cable.

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2.3 Stay arrangement: space system, (modified) fan-

shaped, harp-shaped (parallel-type).

2.4 Anchorage of stays: hot-cast anchorage, cold-cast

or HiAm anchorage, buttonhead anchorage ( looped anchorage (anchoragewith ring plug ( anchorage withwedges (/ anchorage withtapered plug.

2.5 Wire rust prevention: galvanizing; antirust grease,

antirust varnish/lacquer/paint2.6 Stay rust prevention: painting; coiling; sleeve

2 Sunday, June 09, 2013

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3. Features of cable-stayed bridges

A cable-stayed bridge is a highly statically

indeterminate system with high-strength steels, an

orthotropic type deck, development of welding

techniques and progress in structural analysis.

3.1 Advantages of orthotropic deck

3.1.1 It results in the creation of new types of substructure

which can easily carry the horizontal thrust of stay

cables with almost no additional material, even for

very long spans.3.1.2 The stiffened plate with its large cross-sectional area

acts not only as the upper chord of the main girders

and of the transverse beams, but also as the horizontal

plate girder against wind bracings used in old systems.


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3.1.3 All elements of the roadway and secondly parts of the

superstructure participate in the work of the mainbridge system resulting in reduction of the depth of

the girders and economy in the steel.

3.1.4 It is geometrically unchangeable under any load

position on the bridge, and all cables are always in a

state of tension.

3.1.5 It provides the continuity of the deck structure at the

towers and in the center of the main span.

3.2 The important characteristic of the three-dimensional

bridge is the full participation of the transversestructural parts in the work of the main structure in

the longitudinal direction.

3.3 The considerable increase in the inertia moment of the

construction permits a reduction of the depth of the

girders and a consequent saving in steel .

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3.4 Cable-stayed bridges fill the gap that existed between

deck type and suspension bridges.

3.5 The cable-stayed bridges are pleasing in outline , clean

in their anatomical conception and totally free of

meaningless ornamentation.


Bridge (8 1)

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