Bridge and culvert

Bridge and culvert

1. a culvert is made to let water pass through an area by making a circular or rectangular passage
underneath a structure, whether it is a road or any other physical obstacle. While in earlier times,
culverts were mostly made of stone, these days it is common to use, cement, steel, or even PVC to
make culverts. A culvert can be circular in shape (semicircular to be precise as there is floor
beneath), or it can be rectangular, elliptical or pear shaped. It is when two or more pipes are placed
side by side in a culvert so as to enlarge the size up to more than 20 feet that a culvert qualifies to
be labeled as a bridge. There have been numerous accidents because of floods disrupting passage
of traffic above a culvert and in a few cases, the culvert has collapsed.
Most of the bridges in the world are constructed over rivers or other bodies of water to provide
passage to people and vehicles. Despite this similarity, there are differences in design because of
differences in terrain as well as materials that are used for the construction of bridges. A culvert
has an enveloping structure with a floor, two sides and a roof. A bridge does not have a floor and
it sits on foundations along the breadth of the water body.
What is the difference between Bridge and Culvert?
• While culverts are used primarily to allow passage of water across physical obstacles, bridges
are formed to provide passage to people and vehicles over large water bodies
• Bridges have no floors, whereas culverts have a floor and are circular, rectangular, elliptical, or
even square in size
• When it is hard to distinguish between a culvert and a bridge, the deciding factors are the width
of the structure.
A pontoon bridge (or ponton bridge) is a collection of specialized, shallow-draft floats or boats, pinned
together end-to-end to provide rigid connections, and covered with a continuous deck to provide a path
for pedestrians or road for vehicles. The boats or pontoons are lifted by buoyancy, limiting the
maximum load to the total and point buoyancy of the pontoons or boats.
While pontoon bridges are usually temporary structures, some are used for long periods of time.
Permanent floating bridges are useful for sheltered water-crossings where it is not considered
economically feasible to suspend a bridge from anchored piers. Such bridges can require a section that is
elevated, or can be raised or removed, to allow ships to pass.