Beam Bridges
Beam bridges are the simplest bridge type. It can be something as simple as a log over a small stream that you use when hiking or as complicated as the Quebec Point cantilever bridge. Beam bridges can be further divided into simple beams, continuous beams, cantilever beams, and frame bridges. They are often combined together to cross longer distances.
This bridge type features a simple beam that spans from one supporting structure to another. The log example in the paragraph above is a good example of a simple beam.
While the simple design of this bridge makes it economical to construct, it has some disadvantages. The weight of the objects moving overtop of the bridge that can be supported depends on both the strength of the beam used to connect the supports and the distance between the supports. The wider the distance, the stronger the beam has to be.
This is a series of simple beam bridges which share supports, allowing the bridge to span long distances.
A good example of this is the confederation bridge located in eastern Canada.
This bridge type is only fastened to one end; the other end is supported in the air.
Often these types of bridges are found in pairs, supporting a long middle section between them as shown in the diagram below.
These types of bridges are directly connected to vertical supporting members.
See also arch, cable-stayed, moving, suspension and truss bridges.