Help with Site Survey information

[Anonymous]

Okay, so I am a drafts person and I use Revit to draw my houses. When I start drawing I load in a Feature Contour Survey that was produced by the land surveyor. Sometimes I can click on the loaded CAD file (in Revit) and it automatically creates topography, sometimes not and I just have to place points at all the spot elevations and type in the elevation data. I have AutoCAD and sometimes have to tweak some info in CAD so it imports properly into Revit and I have noticed that sometimes the Crosses that mark the spot elevations have a 'Z' value that equals the noted spot elevation.

My question is, is the data collected from a Site Survey actually entered directly into AutoCAD initially or is it taken from another program and imported into AutoCAD and then additional lines for fences, driveways etc. are drawn in. When there is a cross but the Z value is 0 is there a way I can enter the spot elevation value and Revit will then recognize it when imported and make 3D topography?

I unfortunately have no one at my disposal that is proficient in this field to help me at work. If the questions I am asking are more complex than expected, if anyone could suggest an avenue to explore to learn more about this area. I have tried scrolling through the forums and watching You-Tube tutorials but just cannot seem to find the specific answers.

Many thanks.

[Mark_C_123]

Hi,

I bring in survey data as a .CSV using Civil CAD and export to AutoCAD. (It takes a bit of processing)

All shots come in as point crosses with Z values aswell as blocks and any strung lines. So RLs are not manually entered in.

With shots that have a Z of 0, I wouldn't be changing to add heights because How do you know what the correct level is?? 

PS I dont use revit so unsure if there are better ways to do what you want & Can you speak to the surveyor that does the field work? 

Mark

[john.vellek · Accepted solution]

HI @Anonymous,

Its been a while since I did this personally but I used to use a "Camera" on site. This camera would record height and distance of a variety for things include spot points and features such as trees, fences,structures etc. Each item was assigned a code as the survey was recorded.

Then when back in the office, I used software that was configures to recognize the codes when the data was imported into AutoCAD. Points would be placed, linework for features would be drawn and so forth.  All of this would be drawn in three dimensions as that is how the software was configured although it could have "flattened" all the data too.

So, if you are receiving only 2 dimensional data, you would have to enter all the Z data to get it back to a true 3D drawing. Revit is expecting a 3D Contour map.

If you had the Z values, you could use DataExtraction in AutoCAD to write the data to Excel, add the Z values and then in Revit you could import the XYZ values.

Please select the Accept as Solution button if my post solves your issue or answers your question.

[john.vellek]

Hi @Anonymous,

I am checking back to see if my post helped you with your problem or if you need additional assistance or information. Please add a post with how you decide to proceed and your results so other Community members may benefit.

Please hit the Accept as Solution button if my post solves your issue or answers your question.

[Anonymous]

Hi John,

Yes it did, I was also able to contact a site surveyor that my company deals with. I now understand that site surveyors do not use AutoCad to input the data they collect onsite. I have dealt with two file types which have been DXF which the site surveyor said is an older type of file which when sent to me was not three dimensional. I have also recieved DWGs (I am used to dealing with) which have carried three dimensional points (the part I didn't understand) and DWGs work better when importing into Revit than DXFs.

The site surveyors never usually send me the SHX file and now I understand what that is and how to locate it when prompted when opening a file or importing one.

I do not mind that I cannot alter an AutoCad drawing to have three dimensional points (Z Values), I just wanted to know why some files I have been sent have z values and why some don't (depending on the surveyor).

When carrying out my studies I had only learnt AutoCAD in a two dimensional context to draw houses essentially and have never studied the capabilities of how AutoCAD can be a bridge for programs to carry over information to different professions using different programs.

I really appreciate your responses and am happy with my (very) basic understanding of the file types and what information can be transferred across.

[Anonymous]

Oh and I should note as to why I don't mind if the DWG is 2D. All the surveys I get sent have spot elevations and in Revit I can just manually enter all the values for the spot elevations and it creates a topography. But when the DWG is 3D I just literally click create topography from import and it generates the whole topography, so that does save time but as the sites I deal with are never too ridiculously large I don't mind either method.