Retaining walls are commonly employed to retain highly positioned soil, such as soil forming a hill, to provide a usable level surface therebelow such as for playgrounds and yards, or to provide artificial contouring of the landscape which is aesthetically pleasant. Such walls have been made of concrete blocks having various configurations, the blocks generally being stacked one atop another against an earthen embankment with the wall formed by the blocks extending vertically or being formed with a setback. Setback is generally considered to be the distance in which one course of a wall extends beyond the front of the next highest course of the same wall. Concrete blocks have been used to create a wide variety of mortared and mortarless walls. Such blocks are often produced with a generally flat rectangular surface for placement onto the ground or other bearing foundation and for placement onto lower blocks in erecting the wall. Such blocks are also often further characterized by a frontal flat or decoratable surface and a flat planar top for receiving and bearing the next course of blocks forming the wall.
It is generally desired that retaining walls of the type described exhibit certain favorable characteristics, among which may be mentioned the ease with which the retaining wall can be assembled, the stability of the wall (that is, its ability to maintain structural integrity for long periods of time), and the ability of the wall to admit and disburse rainwater. Although retaining wall blocks commonly are supported vertically by resting upon each other, it is important that the blocks be restrained from moving outwardly from the earthen wall that they support.
Current manufacturing techniques and the economics associated therewith limit the shapes, sizes, and materials that may be used to manufacture blocks that still provide the functions described above. In some instances, it would be preferred to make blocks in different shapes, sizes, and colors, and using different quality, types, and price of materials, and possibly in a centralized location which may be further from their point of use. It is desirable to both break through these boundaries and yet produce improved retaining wall blocks.