Who knows shit about fucking discharge in rivers? (G33K POST LOL)

[Teh]

Like seriously?

This isn't an interesting thread or anything yo, but some of you are quite clever and my lecturers fucked off somewhere for the holidays.

So basically, i have this river and it's flooding like fuck and before i design levees, i need to explain all my theory. Gnargh.

I've used Manning's equation to calculate the normal depth, but the thing is the flow is non-uniform, so technically it's not 100% applicable but will give a general estimation of the likely flood levels. The thing that's bothering me is i've then computed a gradually varied flow profile (direct step) from a known depth/starting point up to the chainage where the normal depth occurs- having taken a mean bed slope/gradient (basically a straight line of best fit whereas before it was all jaggy and shit).

So my problem is: does the fact that i've assumed the channel bed to be constant mean that the flow will vary gradually (regardless of whatever it will do in reality) and hence the normal depth will be reached at some point?

/geek

i remember there was a civil engineer on here, i just forgot who, so sorry to bombard you all with this pish.

[Yeti]

Never assume a channel bed to be constant. Sheesh.

[milleson]

*buys a raft and rolls up pants*

Jabumbo was the other civil engineering guy.

edit: Ooh, and I have an article (GSA Today) about this crap. It's from a geologic perpective, but I'll see if I can find it.

[Big Gus]

I've smoked a bong but my first thought was "place an ad in situations vacant for an experienced pack of beavers - trade rates paid".

[Teh]

There's a PhD student in my department called Julie Beever and her topic of study is river barrages.

I'm pure not kidding, man.

yay for google

boo for you guys

[Big Gus]

Julie Beever. LOL.

[Teh]

"Hey, nice Beever!"

[Big Gus]

"Thanks, I just had it stuffed".

[Teh]

i forgot the next line, but it was off topic anyway.

[milleson]

Want to know anything about the sedimentation assemblages associated with your failed levee?

[Teh]

Want to know anything about the sedimentation assemblages associated with your failed levy?

Not really.

I'm considering a two stage channel also with a grout curtain of some sort, so chances are seepage will not be a problem during regular water levels and fuck, ill just make the levees out of steel.


So there! :D

[jabumbo]

steel wouldn't make a better levee



i would just assume its the same, or just tell your professor to fuck off because if this was a real job you would have depths given to you at specified intervals so you could run a proper analysis

[Teh]

steel wouldn't make a better levee



i would just assume its the same, or just tell your professor to fuck off because if this was a real job you would have depths given to you at specified intervals so you could run a proper analysis

When you say it's the 'same', what do you mean?

Is my inital malarky correct?

[HEIRESS]

when I drive my chevy to your levee will it be dry?

how many intake and outtake locations are there along your "river"

[jabumbo]

i'd say your initial assumptions were fine. i think a general gradient line is good enough to get a good enough idea to get you're initial design considerations in, and then you can modify form there.

[Teh]

i'd say your initial assumptions were fine. i think a general gradient line is good enough to get a good enough idea to get you're initial design considerations in, and then you can modify form there.

cheers bro. Just wasn't sure if the mean gradient and constant cross section would mean it'd reach it's normal depth.

What i was aiming to do is that since its low level work, take the river channel as a standard cross section and bed slope as constant, then base a direct step on that to get the entire profile. I just wasn't sure if it would actually reach it's normal depth from manning's with that but yah, i'm just worrying over nothing.

that'll make my day tomorrow. yay.

[milleson]

Is the river straight or curved? That would most definitely change the cross section.

You engineers and your fancy lingo. We could settle this with pictures much quicker.

[Teh]

Well the section i'm working on atm is dead straight.

There's a couple of meanders and a culvert that i've yet to factor in - i'll do that in HecRas, i just wanted to do some calcs by hand to show i actually know something :cool:


(incidentally, i would have never built that thing out of steel) :p

[ET]

Oh, that kind of discharge. nm

[jabumbo]

Is the river straight or curved? That would most definitely change the cross section.

You engineers and your fancy lingo. We could settle this with pictures much quicker.


your attitude is like an overconsolidated clay, so hush up!