"Underpinned" is a word in ENGLISH

To lay stones, masonry, etc., under, as the sills of a building, on which it is to rest.

To support by some solid foundation; to place something underneath for support.

of Underpin

That by which a building is underpinned; the material and construction used for support, introduced beneath a wall already constructed.

The foundation, esp. of a frame house.

The act of one who underpins; the act of supporting by stones, masonry, or the like.