The longest bridges in the world are viaducts or trestle bridges.
It is easier to design a high, elevated roadway by
directly supporting it with many towers or piers (as in a viaduct or trestle bridges).
It is more difficult to design an elevated roadway with a large unobstructed span (as in a suspension bridge or arch bridge).
However, the bridges with the longest unobstructed spans in the world are invariably suspension bridges, because ...
Because they help speed up the Long ******** of ******Traffic
Suspension bridges use steel ropes because steel is very strong and can hold under tension. xxx hope that helps xx
because that is the strongest material?
Arch bridges are in the shape of an upside down "U" with mainly steel beans, while supension bridges have one or two Major verticle beams with strong wire connecting to the bridge.
John Roebling
This question is difficult to answer as "suspension bridge" is a very loose term. Ancient people from South America and the Himalayas have used rope suspension bridges to span chasms since ancient times and there are arguments about who first designed/built the first modern bridges. For information relating to these arguments see the related link below.
Although suspension bridges are among the longest bridges, and most are well-built, the design does include features that make them more susceptible to failure. Rather than a rigidly-connected skeleton, a cable bridge is held in place by its own weight, which maintains a constant tension. The cables supporting the roadway are balanced, and if any fail, the change in weight can cause a complete collapse. Cables must be inspected regularly for corrosion, wear, or slippage. Shifts in the foundation of any bridge can cause it to fall, but because there are fewer supports in the cable bridge, any change will tend to have greater effect. High winds can cause structural failure of a poorly-designed bridge by causing swinging oscillations known as "aeroelastic flutter." This causes a twisting motion that can warp or crumble the bridge deck.
Boats.
For a long spans mainly.
Cables .
i dont know but its strong
wood and hot metal
Arch bridges are in the shape of an upside down "U" with mainly steel beans, while supension bridges have one or two Major verticle beams with strong wire connecting to the bridge.
Cranes that are used for building bridges or other large structures are used because they can carry very large weights across very long spans and heights.
tension :D
tension :D
steel cable suspension
Bridge towers are used in suspension bridges or cable stayed bridges. cables, what hold roadway, are fixed there.
Steel is the most common, especially for suspension bridges. Concrete is used for lower bridges (and where little shifting will occur) because it is more resistant to the elements.
They can be used on fairly long span bridges compared to suspension bridges by using pylons in between. They have better stability against wind loads. They can be constructed in steps working on their own decks.