Abstract: The invention contemplates an earth-anchor or the like structural reference which is cast in cementatious filling at the installation site and which relies upon a particularly characterized bored cavity in the underground medium to permit primary reliance upon the confined compressive strength of the medium, thereby substantially increasing the load capacity of the reference, as compared to prior constructions. To achieve this result, the bored cavity is characterized by one or more wall surfaces of relatively uniform slope with respect to the axis of the bore, the slope being dependent upon the particular medium. The invention is described in application to a foundation pile or caisson, and to an earth anchor, to illustrate compressional and tensional uses.