Civil Engineering Professional Engineer Practice Exam

What unique characteristic defines cantilever bridges?

1. They are supported only at one end

2. They use trusses extending outwards

3. They are always made of steel

4. They support loads only in tension

The correct answer is: They use trusses extending outwards

Cantilever bridges are unique in that they are specifically designed to be supported only at one end, with the other end projecting out into space. This design allows for a great deal of flexibility and strength, as the cantilever arms can extend outward without additional support. The loads applied to the bridge create moments that are balanced by the forces at the fixed support, which is critical to the structural integrity of the bridge. While using trusses extending outward may be a technique seen in some bridge designs, it does not capture the essence of what defines cantilever bridges. It is fundamentally the single-point support at one end that characterizes these structures. Understanding this aspect helps grasp how cantilever bridges can span significant distances while remaining stable.