Abstract: Structural components for constructing a retaining wall, a noise barrier or similar structure are made up of a pair of horizontally extending generally parallel runner elements and connecting elements joining the runner elements together. The downwardly facing lower surface of each runner element has a concave curvature. The concave curvature is made up of a stepped surface which is higher at the outer side of the runner elements than at the inner side. Lines normal to the individual stepped surfaces intersect below the concave surface at a point. The structure components can be stacked one on the other to form a wall backfilled with earth or other material. Sound waves striking against the stepped surfaces are reflected into the slopes of the backfilled material between the individual components.