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.
To strengthen existing walls and foundations.
To pin or support an existing wall by excavating at intervals beneath it and building in piers, after which further excavation is made between the piers and the spaces then are filled with solid walls.
support from beneath
support with evidence or authority or make more certain or confirm; "The stories and claims were born out by the evidence"