I currently have 1m and 5m topography files from Surpac in the format of both DTM and STR and I am tasked to perform a slope stability analysis of the area. I do not have any knowledge to operate Surpac and I only have basic understanding in using both AutoCAD and ArcGIS (ArcMap 10.2).

I have perform some basic slope stability analysis using ArcGIS Slope (Spatial Analysis) before, but the files are in DEM files.

I have Googled around for a while but I could not find a way to open up the DTM files of Surpac in ArcGIS. I have managed to work around a bit by using Surpac to convert both files into SHP files.

But so far what I am seeing is only lines without any height data on them.

Is there a way to convert these DTM and STR data into a usable DEM files which I could run a Slope (Spatial Analysis) command?

As I only have virtually zero knowledge of Surpac and limited knowledge on ArcGIS.

1 Answer 1


If you have a licence of Surpac you can save your STR (string) files as AutoCAD DXF or DWG files. This will preserve the Z elevation values of the STR files allowing you to use the elevations in other software. You could try exporting the DTM surface to an XYZ file or a DXF surface from Surpac.

ArcGIS cannot open Surpac's DTM or STR file formats.

There is a free alternative software called GEM4D that can open Surpac STR and DTM files, although I haven't gotten that particular functionality to work. The software is useful for visualizing DXF and DWG surfaces quickly as well as cutting surfaces and solids against each other.

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