photo by Charles
What is a dam?A dam is a structure built across
a stream, river or estuary to retain water.
There is no unique way to retain water, which is why we see many different shapes
for dams. Some dams are tall and thin, while others are short and thick.
Dams are made from a
variety of materials such as rock, steel and wood. We will concentrate on dams made from
a complex material, because it is important for the construction of large dams.
What is a Societal Structure?
Societal structures are those whose performance - including catastrophic failure - has a
large impact on a significant population.
An obvious example of a societal structure is a bridge.
A bridge provides a large number of people with a convientient way to cross a river.
Another example is a highway, something that isn't usually thought of as a structure but also
needs to be built and maintained because it can affect a large population.
Can you name other societal structures?
photo by Prof. Richard White (#)
traffic cam shot courtesy of
Access Atlanta (#)
Societal structures influence people on a daily basis. People receive or use
the services of a societal structure. These services usually outweigh the problems
of the structure.
People are willing to deal with traffic and construction in order to use their
So there must be particular benefits to each societal structure, including dams.