Dynamic Existing Ground

 

A Profile can be a Civil 3D object of the type Surface Profile or Layout Profile. The difference is that a Surface Profile is associated with a Surface and is dynamically updated when a Surface has changed (or when the trace has been moved) while a Layout Profile is static and is not updated when changes occur. A Layout Profile contains only distances from the starting point of the trace and depth values. By dragging a trace, a Layout Profile will only remain linked to the starting point and will not change substantially.

A dynamic profile line can, however, be changed in the Properties Palette and set as static:

The Profile is no longer automatically updated with changes but can be edited by using grip points:

An originally dynamic Profile can always be restored from static to dynamic. However, any manual adjustments will be lost.