Thursday, January 28, 2010

Storm Pipe Hydraulics

Doing storm pipe hydraulics is one of the most time consuming parts of designing. Here is a few quick tips to save you time. You can create a pipe profile label that can calculate the velocity of your pipe running under pressure flow (full flow slope) with the simple formula of Q/A. I did a post 2 months ago on how to create an expression for calculating area of pipe. One important step is to plug in your Q (flow rate) for each pipe section if you want your labels to work. Once you get into partial flow, the formula to calculate velocity becomes more complex. I have designed an expression for this but I am still running test to make sure all the bugs are out of it before I post it. I also want to add in the Civil 3D help catalog, there is a section covering mannings formula with expressions. Hope this helps you. Later


  1. I did a class at AU last year where I used expressions to calculate the full flow capacity of the pipes. If you or your readers are interested, they can find it here:


  2. Thank you. I will definitely have to check it out.