Copy Shape

Technically, your original shape is never "affected" when you transform a copy:

TopoDS_Shape newShape = oldShape;

The transform simply changes the location of the new shape, but the referenced geometry remains the same.

You can also try using BRepBuilderAPI_GTransform. This will actually create a new, transformed geometry and will not just change the location within the TopoDS_Shape.

Commenter-1

To make a copy of a shape you should use the class
BRepBuilderAPI_Copy.

Something like:

BRepBuilderAPI_Copy A;
A.Perform(aShape);
TopoDS_Shape ShapeCopy;
ShapeCopy=A.Shape();