The parallel seismic method allows one to know the length of a concrete pile, of a barrette, of a moulded wall, of a metallic piling, or of any other buried structure.

The major interest of this method lies in that it can be applied even though the foundation is capped of such a structure as a building or a bridge. Besides, it is not necessary to access the area above the foundation to test : all one needs to access is an area close to the foundation and that is in rigid connection to it.