Video 5 C2: What is a culvert? Flashcards
how are culverts beneficial?
they deal with the conflict between roadways and streams/canals/ditches
what does it mean when a watercourse is ephemeral?
the course only fills when it rains
when you construct a roadway and fill across any low area in the natural landscape, you run the risk of creating an _____
impoundment
if water can’t flow through your embankment, its going to…..
flow over top (hazard to the road itself and the things on the thing such as cars)
whats an obvious solution to impoundment? why is it not always ideal though?
a bridge; costly and not feasible for smaller creaks
since a bridge isn’t always practical to mitigate the conflict between roadway and water, what is the next best option?
to still fill the low area but to place a pipe inside of it to allow the water to travel underneath
what is the pipe called that is placed inside an embankment to get water to move from point A to B?
a culvert
what are the two main jobs of a culvert?
- be able to hold the weight of the overpassing traffic without collapsing
- be able to let enough water pass through so that water doesn’t flow overtop the road
Outlet control happens when… what is the flow limited by?
water can flow into the culvert faster that it can flow out; limited by the roughness/friction or the tailwater depth at the outlet
(Qoutlet<Qinlet, therefore Qoutlet controls)
Inlet control is when…
the culvert inlet is constricting the flow more than any of those other factors (everything that is happening at the inlet controls)
therefore roughness/friction or anything downstream won’t change how much Q is flowing through
if both outlet and inlet are submerged, then _____ could be the control.
either, but normally outlet
if the inlet is submerged and the outlet is full free flow, then _____ is the control (which case?)
outlet; Case b
if the inlet is submerged and the outlet is partially full pipe flow, ____ is the control (which case?)
inlet; Case C
unless you have knowledge of the outlet conditions, usually check both outlet and inlet control conditions, for the maximum allowable ______ or minimum allowable _____
HW elevation; Q
what does a projecting culvert mean?
where the pipe protrudes from the embankment
what is a mitered culvert?
where the pipe is ‘hidden’ inside the embankment- cut flush (can’t see the surface of the pipe as it’s built in)
what is a headwall culvert?
vertical concrete wall with wings sometimes to further direct flow
what is the least efficient type of culvert? why?
the projected culvert; there’s nothing to help guide the flow into the culvert
culverts can vary between inlet or outlet control depending on ____
flow
