Graphics Programs Reference
In-Depth Information
For a gravity pipe network design to be a success, it must meet the following
basic requirements:
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The pipes must be sloped enough for water to flow through them.
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The pipes must be large enough to allow the expected amount of
water to pass.
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The pipes must be far enough underground to avoid being damaged
by freezing or by activities on the site.
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The pipes must not be so far underground that it's cost prohibitive to
install them.
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Structures must be provided that allow people to access the pipes to
perform maintenance.
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In the case of stormwater management, structures must be provided
that allow surface water to enter the pipes.
These requirements relate to two basic types of gravity pipe design components:
structures and pipes. This chapter describes these components as well as their
relationship to each other when represented in a Civil 3D pipe network.
understanding Structures
Structures provide access to the pipes underground. This access can be for people, or
it can be for rainwater that is flowing across the surface of the ground, also known as
runoff
. In the case of stormwater management design, structures called
inlets
or
catch
basins
are placed on the site at locations that are best for collecting runoff. Typically,
the runoff falls through a grate into a concrete chamber and then out through a pipe
toward its final destination. For other types of pipelines, manholes and cleanouts are
placed at predetermined increments so that workers can access the pipes to perform
maintenance. Manholes are also used to create a bend in a pipeline when one pipe
enters in one direction and a second pipe exits in another. Whatever the case, the
placement of these structures is part of the pipe network design process, and it isn't
done arbitrarily.
understanding Pipes
Pipes are used to safely convey water to a predetermined destination. In the case of
stormwater pipes, collected runoff commonly passes through one or more forms
of onsite treatment and then empties into a nearby stream or ditch. In the case of
a sanitary sewer, the journey can be much longer—connecting to a local sewer
main, and then merging with any number of larger and larger mains until the
