Highway Bridge Structures
is asked to think of a bridge, some pretty impressive images usually come to mind.
The Golden Gate and Brooklyn bridges might strike you if you are an American.
Perhaps one would think of the Firth of Forth Bridge if you hailed from the United
Kingdom. For the historically minded, Pont du Gard is almost always a favorite choice.
Without a doubt, these are magnificent structures and volumes have been written
on their history and the engineering behind them; but what of the common highway bridge
structure? Although you probably feel a bump every time your automobile hits an expansion
joint, most people and even many engineers take these average highway bridges for
granted. The common highway bridge structure,
however, is one of the most integral components in any transportation
network. It is also one of the most exciting design projects a civil engineer can
be engaged in. By common highway bridges, we imply structures which typically consist
of a slab-on-stringer configuration crossing relatively short span lengths. The
deck is usually a concrete slab which rests on a set of girders composed of one
of the following types:
❏ Steel rolled sections or plate girders
❏ Prestressed concrete beams
❏ Timber beams
There are a wide variety of other forms of bridge structures in use
(suspension, cable-stayed, arch, truss, concrete, or steel box girder, etc.),
however, the backbone of the modern transportation network is the slab-onstringer
type structure. The Golden Gate, and other major bridges like it, also