Alignment in Grid, convert to ground?

[r_d_clarke]

I'm working on a small bridge replacement project (10m single span bridge) and have been given a proposed alignment that is in grid coordinates.  I also have survey of the ground topography and existing bridge in ground coordinates, tied in to survey control monuments.  The new design has progressed based on the survey in ground coordinates.  

The problem I have is that I would like to convert the proposed alignment (received as a polyline) into ground coordinates to marry up our bridge design with the proposed alignment (done by another firm).  If I scale the alignment to bring it into ground coordinates, the distance between stations is now incorrect (due to being scaled up).  So when I attempt to create an alignment from the scaled-up polyline, Civil 3D of course wants to use actual ground coordinate measurements for the stations.  The new stations created are slightly shorter than those of the scaled up polyline alignment.

Is there a way to get Civil 3D to apply a scale factor to the station labels, so even though a given station on my alignment might be 0+100.052 it would actually label it as 0+100, thus matching the polyline alignment in grid coordinates?

[sboon · Accepted solution]

We have done several of these projects, where one design team does the survey and design of the road in grid while another one deals with bridge sites.  We found that the best practice was to reference the master road alignment and profile, but create a separate alignment for the site.  The master alignment may change stationing as it is designed but the site alignment is fixed, and uses the localized site coordinates to avoid scale issues etc.  We add a station equation to the plans, and show both local and grid coordinates for the site control. 

During construction the bridge contractor works from the site drawings, later the road contractor finishes the approaches using grid data.

Steve
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[r_d_clarke]

Thanks for the insight, Steve!  I think this sounds like a great way to handle this.

Ray