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Earthwork Volumes from Pad Design

PostPosted: Tue Jul 21, 2015 4:45 pm
by AllanJ
Hello.

I am experiencing some unexpected results in my Earthwork Volume reports and I am wondering if anyone may have some insight as to why I am getting these results. I am designing two stockpiles intended to hold 64,000 cubic yards of overburden. My primary concern is the Earthwork Volume report for the larger of the two pads contains a cut volume when the design of the pad should only contain a fill volume on top of the existing ground surface. There should be no cut volume in a perfect fit. A small amount of cut (say under 10 cubic yards) could easily be attributed to imperfections along the plane where the two surfaces come together but I am getting a cut volume in excess of 6000 cubic yards. Is the software telling me I need to cut 6k cy from the ground surface to make the pad contain 54k cy? Is it telling me that I cab accommodate 54k cy on top of the existing 6kcy? I don't understand. This is concerning because I do not know how the total volume of fill is impacted by this value. If I am thinking the design will hold 54,000 cy but in reality will only hold 48,000 cy then I have a HUGE problem. I don't know how to rule out the possibility that the calculation is bogus, or even why I am getting a cut volume of this magnitude in the first place.

I am working in Carlson Survey 2013 with embedded AutoCAD. I have an existing ground surface composed of contours and a .tin file. I am using the Design Pad Template command from the Surface Pull Down Menu. I created a 3D Ployline (all vertices are snapped correctly to elevated elements such as point nodes drawn on Real Z Axis, contour polylines, and tin lines) for the pad boundary polyline. The existing surface is uneven and undulating so I took special care in this step. I am holding an elevation for the constrainer for the Slope Target, Inside Slope Direction, Slope Projection Perpendicular to the Slope Direction, Ratio, and Rounded Exterior corners.

I often get a small cut value from the software when I am calculating volumes from two .tin surface files and have always assumed imperfections in the TINs, and I expected as much this time as well, but this is just excessive. Any insight would be much appreciated.

Thanks!

-Jamie