topic Re: Generate constant slope from one surface to a lower surface in Mining Questions

Generate constant slope from one surface to a lower surface

MikeBickley — Wed, 01 Oct 2014 00:52:29 GMT

Designing a pit slope, I have the footprint of the edge of pit draped on the ground surface (raster) and a second surface (raster) representing the base of the pit. Neither surface are horizontal, uniform or parallel. The issue is how to create the footprint of the base of the pit assuming a constant slope down from the ground surface. Generating that base footprint will then allow me to create a raster between those two polygons and contour the pit sides.

3D Analyst installed.

All suggestions appreciated!

Mike

Re: Generate constant slope from one surface to a lower surface

larryzhang — Mon, 13 Oct 2014 10:37:38 GMT

mike,

your issue is solved aready?

If working with 3D Analyst in ArcGIS for 3D polygon creation (footprint of pit design), please refer to ArcGIS Help (10.2, 10.2.1, and 10.2.2) .

You can edit 2D polygon with attaributes (Z), and then convert into 3D feature class (when needed). When editing the vertices with Z values (at least, 4), please refer to the attachment figure

Re: Generate constant slope from one surface to a lower surface

MikeBickley — Mon, 13 Oct 2014 10:45:53 GMT

Larry,

Many thanks for your reply. So far I have seen no solution and am creating this slope in AutoCAD then importing the surface to ArcMAP. The issue is that the lower surface is not horizontal, it is a sloping and irregular surface. Looking at your diagram, imagine that lower intersect surface sloping rather than having constant elevation.

Mike

Re: Generate constant slope from one surface to a lower surface

larryzhang — Mon, 13 Oct 2014 11:29:31 GMT

I see.

Maybe, it is not bad idea to try differently as below.

You can extract all vertices’ values from the base raster, which are intersected with the lower edge of the slope polygon via the gp at http://resources.arcgis.com/en/help/main/10.2/index.html#//00q900000016000000

Once the vertices’ z values obtained from the base surface, you can edit the slope polygon.

Even not horizontal (a sloping and irregular surface), it can be doneeffectively.

Agreed with you, it is challenging, at least, not efficient, especially, for complex and operational mines or constructions, when using 3DAnalyst in ArcGIS to do ‘open pit design’. Maybe, you already have the book (attachment) at your hand…

Re: Generate constant slope from one surface to a lower surface

MikeBickley — Tue, 14 Oct 2014 10:04:22 GMT

Larry - thanks again for your input. I think the idea of extracting the Z values from the intersection of the slope surface and the lower surface will work. Maybe as ESRI develop 3D and mining / geology-specific tools these tasks will become easier...

Mike

Re: Generate constant slope from one surface to a lower surface

larryzhang — Tue, 14 Oct 2014 11:28:02 GMT

In mining industry, many design engineers are using Surpac, which offers effective workflow to do so, including creating pits, dumps and other surface design features and enable the user to analyse and compare the results very easily.

http://www.gemcomsoftware.com/browse/mine-type/open-pit-operations