Bridge-Cable-Stayed Bridge

Cable-stayed bridge does not only possess high aesthetic value. It also makes slim and long span possible.

Concrete deck is good in compression, and thus it is ideal to sustain the compressive stress developed in deck due to the stays. Prestressing on the other hand, improves the tension and bending resistance of deck section.

Concrete cable-stayed bridge exists in two forms: box girder and beam-and-slab.

The shape of pylon usually resembles “A”, “I” or “H”. When single pylon is provided, the height of pylon above the deck should be around 40% to 50% of main span length. It can be reduced to 20% to 25% by providing two pylons.

There are three common forms of stay arrangement: fan, semi-fan and harp. Fan arrangement enables the stays to work in optimum way, with the drawback of congested anchorage on pylon. Harp arrangement on the other hand, is more aesthetically pleasing, but with less efficient stays. Semi-fan arrangement is somewhere between these arrangements.

For long span bridge, both concrete and steel elements are often used.