Volume Computation Check between Softwares

Volume Computation Formulae Are All Approximate

Only 2 polylines may not be enough unless it is a pup tent.

Send it to me. I'll email you, since you cannot add attachments via BeerLeg.

I will check it in my Carlson and independently.

I'll let you know what method I used.

Paul in PA

Volume Computation Formulae Are All Approximate

Paul,
Great! I just sent it. The polyline is the exterior base of the pile. There are a bunch of points inside the polyline that represent the shots on the pile.

I don't know what kind of discrepancy you are seeing with the owner, but 10% variance between different methods and software would not surprise me.

I am willing to help too, but I am using Carlson. Send me the files anyway if you want to.

If the owner's math is based on a number of truck loads delivered to the pile, might we expect to see a 10 - 15% (swag) compaction of volume of material once it settles onto the pile?

Hey Frank

I'd be interested in running your data in [REDACTED] to try out the updated pile volume feature.

What was the ground contour UNDER the pile? Is there topo available for the location prior to the stockpile. Are you assuming the polyline perimeter represents the surface under the pile? May not make much difference but something to consider. Does he have truck counts for the stockpile? You can have different results even with Carlson. I use volume by layers. offset your perimeter by a small value like .1 horizontal and 0 vertical (3D POLY OFFSET). change that layer to a different layer than the stockpile. Your new layer will represent "Existing" and your stockpile perimeter and top will rfepresent proposed. I usually set my grid size to 10 feet. But... depending on where you pick your bottom left window for "pick entities", you can have slightly different results.

Aerial Photogrammetry with 1-foot contours yields ±2% accuracy. Checked, double-checked and verified for decades.

Did it myself from 1972-1977 about once every other month.

No software, just pushing a dot and tracing with a polar planimeter.

One time, after client sold property, the "lost" quantity was found to have subsided below the original base elevation - it was all there after all.

🙂

I had two people email me on the side, using different programs, and I sent them the files. Their computations are within 1%. 149,000 cy.

Polyline surrounding the base of the pile sets the bottom DTM and is consistent.

Tthat Is A Lot Of Shots And Contours

I doubt my normal method would work. The truncated pyramid calculations works readily for regular shapes, like detention basins and levees.

You had some out of range points, I discarded 5079, 5309, 5340, 5371, 5401, 5402 and 8000.

I set up to create 1' contours without breaking for any labels. Each elevation contour becomes a closed loop. Simply add every polyline area to get a very close approximation of volume. Any open polylines the area is good for the horizontal pie slice.

If I did this on a regular basis I would write a program to list all ployline areas and add them up for me. The actual elevation of each polyline does not even matter. As I read it there are 52 elevations to deal with and not many have more than 1 polyline to deal with.

Paul in PA

That's one he!! of a pile

I did 3 of them this size. Good cardio for sure in 100 deg. LA weather. RTK.

146,382 C.Y. By Adding Contour Areas

I started at the top 148' and worked to the bottom.

When I got to 102' I ran out of closed contours. Would need some extra work along the base polyline.

Had to be careful to subtract the contour area of that hole in the middle that starts at 112'.

Paul in PA

146,382 C.Y. By Adding Contour Areas

Close enough!! THANKS

It is crushed limestone, and the volume of voids are substantial anyway.

> That's one he!! of a pile

That's a small pile around here 😛