Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

Register Log in
  • Congratulations MintJulep on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Search results for query: *

  1. slange

    Preliminary size a ditch

    agreed that is what is messing up my WSE, unfortunately I can't change the size because it is a DOT culvert and they installed it without doing any analysis or anything.
  2. slange

    Preliminary size a ditch

    Thanks, I was thinking about it this weekend. the condition is a backwater/tailwater condition and there is a small amount of slope on the ditch so the water surface profile will be flat and the velocity slow. So, increasing the size of the ditch area will not have an effect. Basically, the...
  3. slange

    Hec Ras Modeling question

    Initially, the flow was extremely wide IE 500' wide. I believe the issue is that the slope for the channelized ditch is very shallow and it is a backwater condition. We can't upsize the culverts going under the road so we have a tailwater condition, plus the land to get from one point to the...
  4. slange

    Hec Ras Modeling question

    In general when you widen a ditch shouldn't the WSE go down in your model? I went from a 75' flat bottom ditch to a 150 flat bottom ditch with 3:1 side slopes and it only dropped the WSE about .09. That seems very small for doubling the size of the ditch. Any input on how I could trouble...
  5. slange

    Preliminary size a ditch

    I need to preliminary size a ditch to contain the floodplain and floodway. I used Chezy Mannings to calculate, and it calculated a Q well over what my hydrology calculated. I then placed in the Hec Ras model and it over tops the ditch, roadway, etc. I know that the downstream structure will...
  6. slange

    Hydraulic Radius and Area of Multiple Box Culverts.(Chezy Mannings)

    One other question why wouldn't you use R = 32/5+32/5+32/5+32/5+32/5= 32 hypothetically doesn't each box have a surface? Just curious?
  7. slange

    Hydraulic Radius and Area of Multiple Box Culverts.(Chezy Mannings)

    So for example you have a CBC and assume flowing full IE 5-8x4 CBC assuming flowing full A=8*4=32 sf ∑A= 32+32+32+32+32= 160 sf P = 4+4+8+8=24 feet r=5*32/5*24=1.33 assuming n=.011, S=.0025 Q = (1.49/.011)(160)(1.33)^.67*(.0025)^.5= 1311.79 cfs
  8. slange

    Hydraulic Radius and Area of Multiple Box Culverts.(Chezy Mannings)

    For a preliminary sizing I have looked at using the Chezy Manning's Equation for box culverts. 1. can you use Chezy Manning's on CBC that are multiple barrels? If yes do you sum up all the areas of each individual box culvert? Do you sum up the hydraulic radius of each individual barrel for...
  9. slange

    Modeling inline lake with Hec Ras Cross Sections

    All, How do you model a lake in HEC RAS that is just upstream from a FIS, has a low flow channel, and overtops and floods an adjacent road during the 100 year event. I have a model set up but don't think that I am modeling the lake right. I believe I need to go the path of setting up a weir...

Part and Inventory Search

Back
Top