Re: Run percentage

[downs482]

Re: Run percentage

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Yeah Im installing a catch basin, and a 18 inch hdpe pipe, the I E at the (top) catch basin is 487.00, then its a distance of 93.00 feet to the outfall which calls for a 480.49 I E, it calls for a 7.00% slope, can you show me how to calculate this, and maybe explain how I can maintain the required 7.00% slope using a standard transit, thank you for any suggestions offered, Michael

[downs482]

Run percentage

I have a pipe I need to install in the ground, the run is 93.00 lf @ 7.00% slope, could anybody share with me the formula for this ? I dont have a lazer That does rise or fall, just a simple transit, HELP ANYBODY ???? thank you THE IE STARTS AT 487.00, AND ENDS AT 480.49

[JohnS]

Originally Posted by downs482

Re: Run percentage

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Yeah Im installing a catch basin, and a 18 inch hdpe pipe, the I E at the (top) catch basin is 487.00, then its a distance of 93.00 feet to the outfall which calls for a 480.49 I E, it calls for a 7.00% slope, can you show me how to calculate this, and maybe explain how I can maintain the required 7.00% slope using a standard transit, thank you for any suggestions offered, Michael

I was hoping a poster named Dirtman would respond as I have no experience with a transit, and I think he does. The 7% slope means for each foot of horizontal run, there is a 7% or 0.07 ft drop or rise. So you would divide the total 93 ft run into a number of stations, say 10, 20, 30, 40, etc feet, and calculate the required drop at each from the starting point, 0.7 ft, 1.4 ft, 2.1 ft, 2.8 ft. The stiffness of the pipe will ensure if you are right at each station, you can't go wrong between.

I can't really speak to the mechanics of using a transit and elevation rod, but you need to get the transit level and use the elevation rod to determine the trench is deepening as required at the successive stations, and no high spots between stations. If your elevation rod is marked in feet and inches instead of decimal feet, use the whole feet and multiply just the decimal fraction by 12 for inches, eg 1.4 ft = 1 foot + 12 x 0.4 = 1 ft 4.8 in.

[downs482]

Yeah thats pretty much how I was planning on doing it as well John, thank you for your time and input in the matter, sincerly, Michael