BUILDING: Earth Retaining Innovation
Recent Western Cape Business News
A brand new shopping complex on the R44 between thriving Stellenbosch and Somerset West in the Western Cape required some innovative earth retaining solutions, both cost effective and compatible with aesthetic/environmental demands.
The cut and fill scenario on the site required two major walls. At the back or delivery side of the building a 6.7m high by 215m long wall at a steep 75 degree angle was required to provide sufficient space for delivery vehicles to operate effectively.
The available space of approximately 2m between the boundary and the kerb-line demanded a gravity wall partially strengthened with reinforced concrete infill. The Terraforce retaining wall system was specified by iCOS, the engineering company responsible for the wall designs, and built on an 800 x 350mm concrete foundation with a Y12 rebar encased in 20mpa concrete, extending to a height of 2.5m, in every 2nd L11 Terraforce block.
Behind the bottom blocks a sub-surface drainage system was installed in combination with cement-stabilized sand backfill. Above that level, a coarse sand drainage layer was specified with a clay cut-off plug and an open drainage channel.
Another similar wall was specified by iCOS for the front or parking side of the centre. This wall is 120m long and 3.8m high, which allowed the foundation size to be reduced to 500 x 350mm.
A total of 13 000 L11 smooth face blocks were delivered to the site. Infill above the reinforced level was specified to be 80% topsoil mixed with 20% 19mm crushed rock for added friction between the rows of blocks. Sub-contractor Dassenberg Retaining Systems finished this R1.2 million contract within three months, experiencing minimal delays due to waiting for services being installed ahead of them.
Today, the walls are virtually invisible, thanks to good plant cover and regular maintenance, and the fact that Terraforce blocks are specifically designed for providing good plant cover, which adds to wall strength and environmental value. Holger Rust, owner of the company, explains the remarkable versatile nature that makes the blocks so popular: “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. The system also allows you a choice between round face, (plant supportive) or flush face (smooth or split version) to suit your specific requirements, and they present a closed vertical surface structure that provides maximum amount of soil mass within the wall and prevents backfill spillage, while at the same time offering uninhibited permeability and plantablity”
Business News Sector Tags:
Fax 2 Email
Study IT Online
Work from Home