The invention relates to a retaining work (12) in ground (S), the work having a vertical front portion and separating a first portion of ground (S1) from a second portion of ground.

The front portion (14) is in the form of juxtaposed arched walls (16), each arched wall (16) presenting a concave side facing the first portion of ground and a convex side facing the second portion of ground, and the retaining work (12) further includes a rear portion (20) comprising a plurality of wall elements (22) having their largest faces extending vertically in the second portion of ground (S2), each wall element (22) being arranged between two adjacent arched walls (16) and extending transversely relative to the front portion (14).

A ballast block has a uniquely designed framework consisting of lightweight, pre-fabricated, metal panel members and cross-bracing and elongated bracing members. The various components of the ballast block framework are compactly bundled and shipped to the end use location for assembly on-site. Once assembled, the ballast block framework is properly positioned on its permanent, end use location and concrete or equivalent ballast material is poured into the framework, completely filling its internal space. The ballast block can be sized and fabricated for the specific desired purpose.