surface

A model representing the original ground, finished earthwork, proposed ground, or other topography of terrain for a certain area. Surfaces are used to plan roadway alignments, calculate cut and fill volumes, and perform other construction operations. A Surface Model can be a single surface or can contain Work Areas inside which Site Improvements are defined. A surface model will have one or more surface boundaries that define its limits, its holes and islands. A surface model can be a simple set of triangles or can comprise the source data for the surface which includes the boundaries, the breaklines, and the points etc. that make up the surface model and that are used to define its shape. The surface Model will carry all of the properties required to construct the surface e.g. layer/lift details, the site improvements and materials, the construction properties for compaction and so on. A 3D surface model can be used for stakeout or grade checking operations.