AutoCAD Civil 3D 2011 - Borehole Importer UKIE Country Kit

[neilyj666]

I need to create surfaces based on depths to various strata in the boreholes and by creating a TIN volume surface between each stratum surface and EG (and Land XML OUT and IN) I can derive TIN surfaces for the strata that follow the ground undulations to some extent.

I've got a csv file in the correct format and using the borehole importer all works fine with the strata extraced to point groups but the depths to strata are negative (as you'd expect). I need the depths to be positive so the TIN volume surface works correctly so is there an easy way to change the depths to be a positive value (export each point group to csv, change them in Excel and import the csv is a possibility but a bit longwinded)??

Thanks

Neil

[SethHall]

Hi Neil-

This may be a bit of a stretch, but did you check the minimum elevation in the surface properties is set low enough to pick up these negative elevation points?

Hope this helps!

[neilyj666]

Hmmmm - thanks for the reply but not sure if it's relevant to this.

The borehole depths are read into Civil 3D as negative values (for obvious reasons) and they can take levels from EGL to create a series of point groups with elevation to the national datum; they can then be used to build a surface if required. However, the problem with this approach is that, for example, in certain circumstances the rockhead could start appearing above ground surface which is not usually desirable.

I would suspect the answer lies in the way that the Borehole importer routine has been written - perhaps extra code should be incorporated to allow the user to specify "positive depths" to allow TIN volume surfaces to be created easily

I did the Excel workaround in the end which worked.

[Anonymous]

Can import your boreholes at meters above sealevel. 

[neilyj666]

Is this a new question or is it related to the above thread??

You create a borehole log file in csv format as detailed in the From the Ground Up blog (has data files to assist in data prep) or import direct from AGS files. The boreholes can be projected to profiles at levels above datum rather than depth below ground