Planning Alternatives (page 1)

TERRAFORCE concrete retaining blocks (crb) are factory made hollow units of uniform strength and dimensions. They have been substantially tested and analysed under field and laboratory conditions and are manufactured under licence by reputable manufacturers on five continents. There are a few types of these systems on the market with elevations ranging from open checkerboard appearance to closed vertical surface structure and many are plant supportive to varying degrees. Some systems are interlinked, while others interlock on the vertical and / or horizontal plane. All systems rely mostly on interblock friction to derive a measure of sliding resistance. Considering the slender cross section of these walls, clearly no amount of interlocking or interlinking will prevent such a structure from collapsing when substantial active lateral earth pressure occurs. The most economical solution under such conditions is often found in constructing a multi-skin gravity retaining wall. Such a wall relies upon weight and frictional resistance to obtain stability. Alternatively earth reinforcing or cement stabilised backfill techniques may be employed.

		Factors influencing installation costs: as wall angles & heights increase likewise. Due consideration has to be given to the presence of groundwater or unstable retained soil.
Light gravity	Heavy Gravity	Terraforce retaining blocks interlock, horizontally as well as vertically with optional keys, and they contain no air voids. They have a closed vertical and open horizontal surface structure. As such they lend themselves ideally to the construction of both light terrace walls as well as gravity retaining walls. The units can be reversed so that a variety of versatile appearances and features can be created.
Composite structure	Vertical/ RC Filled