You can verify this by inspecting the output file.Ģ. The station is totally wrong (backwards), but the reach lengths are right, except that they look upstream instead of downstream (so the upstream section has length 0). Civil 3D exports each cross section with geometry, a river station, and reach lengths. Let me know if this sounds rigorously correct.ġ. Your concerned occurred to me too for a while, but it's mistaken, and it's not easy to explain why (probably because I have not thought it out rigorously myself, or I have forgotten). Very helpful, but one thing I noticed you should reverse the order of the downstream reach lengths in the same way you reversed the river stations otherwise just moving them up one row doesn't accurately represent the downstream lengths unless all your cross sections are spaced the same distance. This comment has been removed by a blog administrator. Station 10, 20, 30 (flow direction in hecras = ) When you do this you give the station negativ values and so the highest value gets the lowest -) replace all text "STATION: " with "STATION: -" open the exported xxx.geo with the text-editorģ. One of the most easy way to change the names of the stations when exporting from cad to hecras is:ġ. Maybe the bug has been fixed since c3D 2014? Here is an Autodesk forum post where I commented on the bug in 2010, and again in 2014: One thing you need to be aware of: if you have skewed or dog-leg cross sections, the surface line data in RAS won't track with the "cut line"- the surface will be for a straight cross section, exactly perpendicular to the stream centerline, while the cut line will be where you want it to be.
This stream has its narrower bank on the left, imported correctly. Sections run left to right (looking downstream) and your banks are in In the Geometric Data, View, View Options, Cross Section PropertiesĪrea, turn on the XS Direction Arrows check box. Then paste the resulting list (no reversing needed) back into the Cross Sections and IB Nodes, Import As column. Use spreadsheet to fix cross section River Stations You may want to copy the stations to a LibreOffice (Go, Free/Libre Open Source Software!) spreadsheet, and subtract each River Station from the highest River Station. They will increase from upstream to downstream, which will make HEC-RAS calculate your stream backwards. If you want, use the tools in the Cross Sections and IB Nodes tab to assign river stations to the sections, but DO NOT import yet.
The finished sample lines should all start on the left and run to the right. After you select the alignment, a toolbox appears where you can choose to create the sample lines from polylines. They should cross (not end at or short of) the centerline. We will address the downstream to upstream hydraulic calculations later. Having it point downstream is important so that the cross sections and banks read correctly from left to right looking downstream. Create a Civil 3D alignment from the polyline, and use the Reverse Alignment Direction tool if necessary so that the stations increase going downstream. Draw a stream alignment polyline (direction is not important).
Start with a ground surface that completely encompasses both the river alignment and the cross sections. But the general idea works with earlier Civil 3D and HEC-RAS 4. dwg file.Note: These were written toward Civil 3D 2016 and HEC-RAS 5. Use the Export to CAD tool to export both the point and 3D line shapefiles to a.This functionality can be accomplished using Add Field and making simple field calculations. To learn more about how this tool works click here. This is a deprecated tool at version 10 and later.
Click the box next to contour and select 'TxtValue'. This is found in ArcToolbox > Conversion Tools > To CAD > Set CAD Alias. Use the Set CAD Alias tool to assign TxtValue to the field that contains the contour values.Convert the 3D layer to points using the ArcToolbox > Data Management Tools > Features > Feature to Point tool.Use the 'contour' field as the source of heights. Open the 3D Analyst drop-down menu > Convert > Features to 3D.
Instructions provided describe how to convert contour lines to CAD format, while preserving elevation values. How To: Convert contour lines to CAD format Summary