Description: Truss bridges utilize horizontal beams at two different heights. The bottom
and top beams are connected by a series of vertical and angled beams. The
top beam and the vertical connections to the bottom beam are in compression
(being pressed inward from the ends) while the bottom beam and the angled
beams connected to the top beam are in tension (the ends of the beams are
being pulled away from each other). The two level structure gives the
bridge rigidity that a single level beam bridge does not have, and thus
truss bridges can have longer spans than simple beam bridges when using the
same type of material to construct the bridge. |
