because of the support of the circles
Yes
No
An arch bridge. I think that may have been discovered quite some time ago !!! +++ It was - the Romans used arches extensively, in buildings as a well as for bridges. However, the arch is indeed stronger than the plank, or simple beam, bridge because it transmits the loads to its abutments. You can stiffen a beam bridge by fitting it with vertical side-members, or in larger structures, frames (trusses).
Because it has more support in its arches.
the truss bridge is strong because each side supports the next one over, as that one supports the next one over, as that one supports the first one. I'm not sure on this part, but I think it is a lot more stable than a square because it also has the strength of the arch.
Yes. An arch bridge is one of the more efficient ways of building and maintaining a bridge. Beam bridges are not as efficient. For a given span and height, an arch bridge will carry a greater load using less material. The beam structures of a beam bridge can be constructed of wood, reinforced concrete or steel (in increasing order of strength). The beams, however, must be supported by piers or an abutment at each end, which can be made out of concrete, masonry, stone, or steel (or combination thereof). The arch structure of an arch bridge can be constructed of wood, reinforced concrete, steel, or masonry, and the arch can be supported by abutments as described above, or the arch can extended down to the foundation itself. The primary advantage of an arch is that stresses caused by the load on the bridge are converted primarily into compressive stresses that are carried along the arch into the ground. Materials like stone, masonry and concrete are particularly good at carrying these compressive stresses. In contrast, loads on a typical beam-type bridge creates large tensile stresses on the bottom of the beams. Since stone, masonry and unreinforced concrete have very little capacity to withstand tension, none of these materials can be used to make a reliable and efficient beam-type bridge of any significant span.
Yes, because the mathematical process they used in that architecture was really well done. +++ Not inherently so, it isn't. The design mathematics are fully understood for any bridge type, and the individual bridge is designed for its own location and intended loads (plus safety factor).
Yes there were truss bridges in Europe before the United States. Truss bridges formed in the US because of Europeans, but new American designs were made and that is why the truss bridge is more abundant in the US than Europe today.
As strong as you make it... Basically a truss system is used when a beam cannot hold its load, so is one way of 'reinforcing' a beam (you could have more supporting colums or use cable stayed/suspension techniques). Its basically stronger than a beam, and 'weaker' than a suspension bridge, but to be honest it's basically as strong as you engineer it. Try searching truss bridge on wikipedia... there's lots of different types and I'm sure it'l have the info.
Bridges are made up of triangles joined together to form a truss. Triangles are very strong because they carry weight in tension and compression instead of bending and can hold a lot more than a beam that bends can
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.
because it is less stronger than the sides of the bridge.
Arch bridges are better because they transfer the weight down the archs and into the grownd unlike the beam bridge where it transfers it's weight through the beams wich break more often than arch bridges. Arch bridges are better because they transfer the weight down the archs and into the grownd unlike the beam bridge where it transfers it's weight through the beams wich break more often than arch bridges.