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 TugboatEng 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. beej67

    Baltimore Bridge collapse after ship collision

    TugboatEng, what's your pro take on the prop walk theory a couple of folks have proffered above? It rings true to me but I'm way out of my element. Not-very-enlightening side comments: 1) If I dropped anchor on my old 32 ft sailboat while at an 8 knot clip that would have severely messed my...
  2. beej67

    Is it standard FEMA practice to smooth out a dip in a flood profile that's due to choking or a jump?

    I think I found my answer. https://www.fema.gov/sites/default/files/2020-02/FEMAPolicyStandardsforFloodRiskAnalysisandMappingNov2019_0.pdf Seems like Working Standard #79 states explicitly that flood profiles shall not rise from an upstream to a downstream direction. Hydrology, Drainage...
  3. beej67

    Drainage Before and After Development

    I would not prove compliance with a pre/post match by monkeying with your Tcs in rational method, because it's disingenuous. In rational method, Tc is merely dictating which storm you use for your analysis, which means doing a pre/post analysis with different Tcs in rational method means you'd...
  4. beej67

    Good Calculator/Spreadsheet for Determining if road gutter runoff will blow past a catchbasin

    TerryScan nails it. Here's the download link: https://www.fhwa.dot.gov/engineering/hydraulics/software/toolbox404.cfm Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East - http://www.campbellcivil.com
  5. beej67

    Is it standard FEMA practice to smooth out a dip in a flood profile that's due to choking or a jump?

    Situation: I'm doing a CLOMR based on an effective model given to me by the local county floodplain manager, who is an experienced PE contract guy from a big firm. He says it's the effective model. FEMA says they don't believe it's the effective model and want me to spend the months and/or...
  6. beej67

    Climate change considered in flood modelling

    Some of the best evaluations of climate scenarios come out of Judith Curry's website in my opinion. This article states that RCP8.5 is not very likely at all, and RCP2.6 may be the best thing to use in terms of future predictions if you were setting overall climate policy...
  7. beej67

    What tools are available to streamline conversion of old jacked up FEMA PDFs into HEC-2 input files?

    That's where we got it. FEMA said "here's your model" and sent us PDF scans that looked like that, with no digital copy of the input or output files themselves. Therein lies the rub. If we applied for a CLOMR with a "from scratch" HEC-RAS model of our project area that tied visually with the...
  8. beej67

    What tools are available to streamline conversion of old jacked up FEMA PDFs into HEC-2 input files?

    Yeah, I'd love to do that, but can't because of inter-agency and inter-engineer politics. A current georeferenced HEC-RAS model exists for this reach, done by one of the big companies (y'all know them, begins with a D) and their model was developed for the county but they never took it to LOMR...
  9. beej67

    What tools are available to streamline conversion of old jacked up FEMA PDFs into HEC-2 input files?

    I, in my naiveite, had thought that my days trying to do flood studies off of old, nearly illegible HEC-2 printouts without any digital backup data were long gone. Unfortunately, this appears not to be the case, and I seek advice and assistance. If you're as old as me you've seen things like...
  10. beej67

    Miami Beach, Champlain Towers South apartment building collapse

    Shooting from the hip - If I had to guess I'd say this was a foundation failure due to subsurface karst topography. Stormwater management in Miami Dade SFWMD is usually done (or at least as of the mid 2000s) with infiltration pipes and baffles into the sandy subsurface aquifer. If the pH of...
  11. beej67

    Which attorneys do I call?

    This was my exact thought, but I needed to suss out when the point of pivot was, from "help my client's lawyers on an hourly basis" to "sorry I have to get my own attorney now." Sounds like the moment I'm named on paper is that time. What are the general odds that the insurance company's...
  12. beej67

    Which attorneys do I call?

    I did a hydrology study for a land development project a few years back. I was subbed to another engineering firm. Highly urbanized watershed, very flashy floods, which drains down into a ritzy part of town. Apparently an attorney who owns a home downstream of the project just got flooded out...
  13. beej67

    Problem entering manual hydrographs into a link for multiple storm events

    Hot dog, thanks for the help. Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East - http://www.campbellcivil.com
  14. beej67

    Problem entering manual hydrographs into a link for multiple storm events

    I'm sure this is probably like when you're staring into the refrigerator right at the ketchup and still can't find it, but is it in another tab than the manual tab? Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East -...
  15. beej67

    Pond design for multiple storm events to achieve the desired flows

    This should be very easy to do manually if your pond is big enough. Like, ten minutes tops. If you're struggling with it, take a step back and do this. Throw your pond stage storage out for a moment. Draw in a vertical box that's got a lot of volume in it. Use one slot weir and nothing else...
  16. beej67

    Problem entering manual hydrographs into a link for multiple storm events

    I have a project with multiple storms defined within it (named "1" "2" "5" etc) I create a new link. I select "Link Type (enter hydrograph manually)" The "Manual" tab appears Under the "event" dropdown I select "1" I enter a flow at 0.0 hours (I only want constant flows for each event) I click...
  17. beej67

    Hydraulic open channel modeling question HEC-RAS? SWMM?

    If it were me, I'd do SWMM for the 10 and 50 and HEC-RAS for the 100. In the SWMM model I'd have the large swale as one node (or a trapezoidal reach with the geometry buried in the link instead of the node) with a culvert tied in to the main channel, being sure to allow backwater effects to...
  18. beej67

    How to calculate required storage volume with EPA SWMM 5.1?

    To be clear, if you're doing the method gbam suggests, you start at zero and draw a line up and to the right at an angle, intersecting with the point at which the receeding limb of the proposed hydrograph equals the target outflow. Also to be clear, this is an estimate. To get your actual...
  19. beej67

    Stamping Old Stamped Plans

    You might not even be allowed to stamp his plans, for copyright reasons. Presuming you're comfortable that the design is still good, I'd ask the municipality if they'd be okay with you writing them a letter stating you've reviewed the plans and find them in conformance, and then stamp the...
  20. beej67

    Methods for Generating Hydrograph for Large Drainage Areas

    I'm sure Flo-2d has a direct hydrograph input option, where you can import time series data generated by HMS. The question is what method to use. NEH 630 Chapter 10 (above link) outlines the NRCS method (aka SCS method) which is what we usually use for watersheds smaller than that. Chapter 16...

Part and Inventory Search

Back
Top