Patent ID: 7677841

Claim:
A method of building a retaining wall structure, the method comprising: arranging a plurality of first retaining units adjacent to each other in a horizontal direction to form a first horizontal retaining wall layer; arranging a plurality of second retaining units adjacent to each other in a horizontal direction on the first horizontal retaining wall layer to form a second horizontal retaining wall layer on the first horizontal retaining wall layer that is parallel to the first horizontal retaining wall layer; arranging a plurality of third retaining units adjacent to each other in a horizontal direction on the second horizontal retaining wall layer to form a third horizontal retaining wall layer on the second horizontal retaining wall layer that is parallel to the second horizontal retaining wall layer; coupling the first, second and third horizontal retaining wall layers with one of a plurality of supporting, members, wherein each supporting member includes a pair of downward protrusions spaced apart and each extending in a first direction and a coupling portion that connects respective proximal ends of the pair of downward protrusions, wherein coupling the first, second and third horizontal retaining wall layers comprises driving the pair of downward protrusions through one of the plurality of third retaining units, through a corresponding one of the plurality of second retaining units, and into a corresponding one of the plurality of first retaining units, with the coupling portion positioned on an upper surface of the third horizontal retaining wall layer; arranging a plurality of fourth retaining units adjacent to each other in a horizontal direction on the third horizontal retaining wall layer to form a fourth horizontal retaining wall layer on the third horizontal retaining wall layer that is parallel to the third horizontal retaining wall layer; and coupling the second, third and fourth horizontal retaining wall layers with another of the plurality of supporting members, comprising driving the pair of downward protrusions through one of the plurality of fourth retaining units, through a corresponding one of the plurality of third retaining units, and into a corresponding one of the plurality of second retaining units, with the coupling portion positioned on an upper surface of the fourth horizontal retaining wall layer.