Retaining walls are often used to create more usable, durable areas for building homes and roads on land that would otherwise be inaccessible. They also lend themselves well as a cost-effective and versatile method for creating building platforms, access steps and road support for low cost housing, or as in this case, relocating informal settlers to new IRDP houses made with CRB blocks.
In 2014 Dassenberg Retaining was approached by the Theewaterskloof Municipality to provide a solution for storm water management, access steps and erosion control between constructions levels at a new IRDP housing site in Botrivier, Western Cape.
During construction of the site, various levels were cut and services installed, creating exposed embankments, that would erode and undermine the aprons around the houses.
This required several Terraforce L12 retaining walls between one and two meters in height, all 20 meters long, with footing and subsurface drains in front and behind the walls.
A number of one meter wide steps, using the Terraforce 4×4 Step block and L12 blocks as end stops, were also added to provide pedestrians with access between the levels.
In addition, cut off drains were added to some areas of the housing site, with Terracrete permeable pavers, to manage water run-off during the rainy season. The one meter Terracrete channels were placed on A2 filter material, and the blocks filled with excavated material.
The retaining blocks used at the Botrivier site were pioneered by Terraforce – a Cape Town based pre-cast concrete licensor – almost 40 years ago, and represents one of the most energy efficient segmental retaining wall systems.
Says Georg Brand of Dassenberg Retaining: “What makes this product so popular in the industry is that the blocks require low hardware input for manufacture, low transport costs and low inventory requirements at sales outlets. They are hollow, yet strong enough, and require less concrete to do the job when compared to solid block systems, which of course saves money”
He adds that: “concrete retaining walls constructed using the Terraforce system are easily formed into complex curved shapes or into walls in which the upper and lower profiles are continuously changing, while the system also allows you a choice between round face, (plant supportive) or flush face (smooth or split version) to suit specific requirements. Above all, they present a closed vertical surface structure that provides maximum amount of soil mass within the wall, which prevents backfill spillage, while at the same time offering uninhibited permeability.”
In total 6905 Terracrete, 8531 L12 and 1030 4×4 Step blocks were installed on site.
Contact Dassenberg Retaining for more information on retaining walls in the Cape region:
Tel: 021 987 2233