It is any type of support beam or structure.
portion of the bridge above the roadbed?
the substructure-gogodude32
span
Superstructure
Yes, it is like a bridge, but it is generally a natural formation. A causeway is a raised roadway or roadbed or natural bridge, usually over a body of water. A "bridge", in the majority of cases implies a man-made structure.
it protects from tension and compression
No it's not it's a noun.
A drawbridge. There are different types of draw bridges. A bridge that lifts the roadbed straight up along two towers is called a lift bridge. One that tilts one side or the other using a cantilever system is called a cantilever bridge. A bridge that pivots the span from its center allowing vessels to pass on either side is called a swing bridge. All these bridges are considered draw bridges.
The Bridge. See Wikipedia article on Song Structure, linked below.
Usually it is located on the same level as or one level below the main navigation bridge, giving the captain quick access to the bridge if required.
Donghai bridge is a kind of mixed-kind bridge. The first part is the arch bridge. The middle one is the suspension bridge and the last part is the arch bridge.
The Mackinaw Bridge is a 5 mile long bridge that connects the lower part of Michigan to the upper part
The meaning of the below cartoon is that we created the League of Nations, but refused to join in. We did not take part in the "bridge" that we had created.