SSA for spillway

[derryck1234]

I want to run a simulation for a spillway to compare Civil 3d's analysis with HEC-RAS.

I thought that it would be possible to simply use an open channel as a link. My problem is that I want to have various links so that I can create different slopes for each link.

My problem comes when I need to have a node at each end of a link. If I put a man hole, all the program asks for is the invert and cover level of the man-hole...what about the other dimensions (i.e. cross section)? Ideally I want no man-hole at all, just a simple change in grade...so I would put the cover level very high...

What would you suggest? Should I maybe rather design the spillway in Civil 3D somehow? I am just not sure how to do this...and can I even run a simulation in CIVIL 3d?

Regards

Derryck

[wfberry]

Perhaps a Junction would be a valid choice.

Bill

[derryck1234]

Hi Bill

I put in manholes...because in my SSA, the 'junction' button always refers to a manhole...why can I not enter a cross section for a manhole/junction? All I can enter is the invert and cover elevation? What is the default cross section of the manhole/junction then? Does it even have one?

Yesterday I ran the system with manholes...it seemed to run fiine...but I have a question...The peak run-off (in cumecs) was less than the peak run-offs in my conveyence links? How is this possible?

Regards

Derryck

[Hidden_Brain]

i believe the junction represents a 4' internal diameter manhole.