The bridge began as a felled log supported by the river banks
A beam bridge works on the principles of compression and tension
The top reaches maximum compression. and the bottom snaps under too much tension
Truss Bridges!
Is a bridge whose load-bearing superstructure is composed of truss
is a structure of connected elements, forming triangular units
are the oldest type of modern bridges
are assumed to be pin jointed where straight components meet
Cantilever Bridge!
A bridge built using cantilever, structures that project horizontally into space, supported on only one end.
Large cantilever bridges designed to handle road or rail traffic
The steel truss cantilever bridge was a major engineering breakthrough when first put into practice
A simple cantilever span is formed by two cantilever arms extending from opposite sides of an obstacle to be crossed, meeting at the center
A cantilever bridge could be said to be a variation on the basic beam bridge.
arch Bridges!
An arch bridge is a bridge with abutments at each end shaped as a curved arch.
Arch bridges work by transferring the weight of the bridge and its loads partially into a horizontal thrust restrained by the abutments at either side.
Possibly the oldest existing arch bridge is the MycenaeanArkadiko bridge in Greece from about 1300 BC
Arch bridges are one of the oldest types of bridges and have been around for thousands of years
They were originally built of stone or brick but these days are built of reinforced concrete or steel.
suspension bridges!
A suspension bridge is a type of bridge in which the deck (the load-bearing portion) is hung below suspension cables on vertical suspenders
This type of bridge has cables suspended between towers, plus vertical suspendercables that carry the weight of the deck below, upon which traffic crosses.
The suspension cables must be anchored at each end of the bridge
he main cables continue beyond the pillars to deck-level supports, and further continue to connections with anchors in the ground
In some circumstances the towers may sit on a bluff or canyon edge where the road may proceed directly to the main span
cable-Stayed Bridges!
A cable-stayed bridge is a bridge that consists of one or more columns with cables supporting the bridge deck.
In a harp design, the cables are made nearly parallel by attaching them to various points on the towers so that the height of attachment of each cable on the tower is similar to the distance from the tower along the roadway to its lower attachment.
In a fan design, the cables all connect to or pass over the top of the towers
Compared to other bridge types, the cable-stayed is optimal for spans longer than typically seen in cantilever bridges, and shorter than those typically requiring a suspension bridge.