The road deck's symmetrical construction balances the weight, minimizing the need for extensive ground anchorages. In summary, cable-stayed bridges bear the road-deck weight differently than suspension bridges, are faster to build, and use fewer building resources. They are also less expensive to operate and maintain.
Cable-stayed bridges are composed of two main parts: a vertical tower and a horizontal cross-beam. The vertical part of the tower includes the base, where it connects to the surrounding earth or concrete structure; the body, which contains one or more lanes of traffic; and the top, which provides an open area for viewing the sky or offering a view of the city. The horizontal beam connects to the top of the vertical part at an angle, forming an "X" shape when viewed from the side. It supports the roof of the bridge, which may be made of material such as steel or concrete. The length of the beam determines how many lanes the bridge can hold. Short beams support few lanes while long beams support many lanes.
Bridge engineers design cable-stayed bridges with varying degrees of curvature in order to meet various safety requirements and traffic demands. If the radius of a curve is too great, then the vehicle crossing it will experience a large amount of force due to gravity. This force can cause vehicles to have more difficulty stopping or turning, especially if they are approaching the curve from either direction.
Cable-stayed bridges are significantly less expensive for road-deck lengths ranging from 500 to 3,000 feet (the Bridge Project's primary span is 2,000 feet), and they can be completed in far less time. They employ less steel wire and more precast concrete pieces, which speeds up construction. Cable-stayed bridges also require fewer piers than suspension bridges of equal length because they use vertical support cables instead of horizontal trusses.
A cable-stayed bridge's vertical support cables usually come from the top down, like a chandelier. The ends of each cable attach to cylindrical towers that stand on end like giant candles, with the bottoms attached to the ground. As a vehicle drives under the bridge, the weight of the vehicle pulls on the cables, which in turn raises or lowers the center of the bridge, just like a seesaw. Any type of vehicle can cross a cable-stayed bridge, including large trucks, but their weight affects the height of the deck above the waterway. Bridges with lower decks are generally preferred by freight carriers due to having no need to raise heavy cargo containers off the truck beds for transport.
The main advantage of a suspension bridge is its ability to carry much heavier loads over much longer distances than cable-stayed bridges. A typical suspension bridge consists of multiple sections of steel girders connected by thick wires called "truces".
The suspension bridge A cable-stayed bridge is a type of bridge in which the deck's weight is supported by a series of almost straight diagonal cables in tension going directly to one or more vertical towers. Vertical compression is used by the towers to convey cable forces to the foundations. The central portion of each tower forms a chamber where the cables are stored when not in use.
The term "cable-stayed" comes from the fact that these bridges usually have two pairs of cables, one pair being used as a stay for the other pair. Thus, they serve as both support and swing span for the roadbed beneath them.
There are several types of cable-stayed bridges, depending on how the towers are connected to the rest of the structure: jointed, gussetted, and integral. A jointed cable-stayed bridge has two parallel main cables and two cross-cables connecting the two main cables at regular intervals. As the name suggests, these bridges are made up of many separate sections or joints that can be assembled into a single unit. They are most commonly seen in Europe but also exist in North America. A gussetted cable-stayed bridge has three main cables and three cross-cables connecting the three main cables at regular intervals. These bridges are also made up of many separate sections or gussets that can be assembled together into a single unit.
The static system of a cable-stayed bridge might vary depending on the circumstances of deck support at the abutments and the presence of piers in the side spans. The link between the deck and the tower is also crucial. This mechanism largely influences how well the structure supports live loads. A cable stayed bridge with piers will usually have its own separate division between its main truss and its side girders. These may be called the masthead, deckhead, or main girders.
Cable stayed bridges are particularly useful where site conditions do not allow for the construction of large concrete towers. They can also be used where it is desirable to keep the height of the bridge low compared to other types of bridge structures. The side girders of a cable-stayed bridge converge at their top edges into small caps that fit over the tops of the side piers. These caps are called "masts". The distance between the tops of the masts and the bridge deck is called the "masthead clearance". There should be at least 3 inches of space between the mastheads and any overhead obstructions such as power lines.
The side girders of a cable-stayed bridge are attached to the top of the piers using connectors called "fastenings". The bottom ends of the side girders rest on bearing surfaces called "abutments" which anchor it to the ground or to another bridge component.