Offset surface perpendicularly

Is there a way to offset a surface perpendicularly upwards? I have a job at the moment where we have created a smoothed batter design on an existing dam wall but it is then getting a 300mm sand blanket laid on the face which is measured perpendicularly off the surface and not as a vertical offset. It’s not a simple matter of calculating the horizontal / vertical offset to create the 300mm as the existing batter slope is not at a uniform slope.


The only place in TBC I’m aware of that can do a perpendicular offset is within the takeoff module. You can setup a site improvement with a depth and then choose whether that depth is measured vertical or perpendicular.

Hi Wayne

Thanks for the response. I’ve tried that but it only works from the top down. I am looking to offset upwards

Will it take a negative “depth”?

No, unfortunately not

If the surface was created from a corridor. One thought would be to create a new alignment. Using the original alignment, create an offset of the vertical to the delta you need and use the new offset line as your new vertical for that new alignment. Then you would change the alignment being used in the corridor template. If you’re using a corridor.

Or just explode or the extract surface feature from the surface if you only have the surface to extract breaklines. Those break line can then have a delta added to them. New surface is now elevated upwards.