A continuous beam is a structural component that provides resistance to bending when a load or force is applied. These beams are commonly used in bridges. A beam of this type has more than two points of support along its length. These are usually in the same horizontal plane, and the spans between the supports are in one straight line.
In contrast to a simply supported beam, which has supports at each end and a load that is distributed in some way along its length, a continuous beam is much stiffer and stronger. A bridge that is made up of beams that span between only two supports is called a simply supported beam bridge. If two or more beams are joined together rigidly over multiple supports, the bridge becomes continuous.
The two main factors for consideration in the design of a continuous beam are the type of load and the strength characteristics of the material used to construct the beam. The reactions that occur at the supports of a simply supported beam can be determined by analyzing only the forces applied to the beam. For this reason, simple beams are known as statically determinate. A continuous beam has more supports than are required to provide equilibrium, and the deformation behavior under load is also considered when determining the support reactions. As a result, this type of beam is known as statically indeterminate.