Menu: Files->Import→DXF>Import->DXF...
With this option it is possible to read a file in DXF format (AutoCAD exchange format).
GiD is able to read most of the entities, which are: POINT, LINE, ARC, CIRCLE, ELLIPSE, SPLINE, LWPOLYLINE, MLINE, POLYLINE, VERTEX, TRACE, SOLID, 3DFACE, 3DSOLID, BLOCK, INSERT
A very important parameter to consider is how the points must be joined. This means that points that are close to each other must be converted to a single point. This is done by defining the variable ImportTolerance (see Preferences). Points closer together than ImportTolerance will be considered as a single point. Straight lines that share both points are also converted to a single line.
You can use the Collapse function (see Collapse) to join more entities.