Munyaka Lifestyle Estate

RETAINING WALLS, CONCRETE STAIRCASES AND WATER CHANNELS AT MUNYAKA LIFESTYLE ESTATE IN WATERFALL CITY

Valcal provided the design and specifications for the retaining walls and were responsible for the full installation at the Munyaka Lifestyle Estate in Waterfall City, Pretoria. This multiuse development by Balwin Properties consists of over 5000 apartments, a lagoon, and Lifestyle Centre which offers free gym facilities, squash courts, on-site concierge, restaurants, meeting rooms, a heated swimming pool, laundromats, cinema, wellness spa and children’s play area, and is expected to be completed over an 8 year period.

Using Retaining Wall Blocks, which have been designed as the perfect solution to the widest possible range of soil retention and landscaping requirements, Valcal were able to add an aesthetic value to the project which positively contributes to the developments green rating. The project included the installation of retaining wall blocks, water channels, slider panels and concrete staircases.

This project located on Modderfontein Road & Emerald Boulevard, included retaining walls and an attenuation pond which was completed mid-2012. The retaining wall structure was comprised of Remblok 30 and extension pieces which provided an aesthetically pleasing look whilst the extension pieces provided the required design strength for the height of this retaining wall. Together with the reinforced fill-layers it created a monolithic structure. At the time of this project construction the Remblok was the only holder of the SABS SANS508 mark which subsequently set the benchmark for other producers to follow.

Construction challenges at this site predominately surrounded the mixed spoil material on the site which did not meet specified standards. In order to, mechanically strengthen the poor in-situ spoil material, crushed concrete was mixed with the waste material on a 50:50 ratio to reach a C4 specification fill.

This retaining wall was constructed with Infraset TB300 block system, which is a dry stacking, interlocking retaining wall.  The Infraset TB300 system provides structural stability without the need for concrete infill and is a versatility and adaptable retaining wall system.  The client sought an aesthetically pleasing retaining wall that could be created into a green-belt.  The unique open bottom hole design and trough shape of the Infraset TB 300 system promotes rapid plant growth as the roots are unrestricted which aids in the stabilisation of the embankment.  By using the TB300 system for Christal Construction we were able to construct a retaining wall to meet with the structural requirements for the site as well as a natural environment to promote a greenhouse effect for the vegetation.

An attenuation pond was constructed to attenuate storm water and manage the disbursement of rain to prevent flooding and more severe downstream damage.   Attenuation ponds are a prerequisite for all new developments.

The advantages of constructing an attenuation pond with retaining blocks is in the economy, speed of construction, labour intensiveness and flexibility that retaining blocks offer.

This attenuation pond was constructed using Terraforce blocks which provide an automatic closed face system – providing a better process during construction around curves. 19mm Stone was also used behind the blocks with a water transmissive geofabric to facilitate controlled drainage due to rapid draw down, but specifically to prevent soil contamination behind the retaining wall during heavy rains or flash storms.  This ensures that the structure remains sounds for the entire design life.

This retaining wall gives the impression of a normal cladded wall and nearly looks erect which is a special feature of a Terrafoce Rock Face option ™ retaining wall.  This site also called for a retaining wall system that dealt with the heavy duty soil erosion and one that provided adequate sediment control.  The Terrafoce Rock Face L11 system is highly effective in providing erosion control and the vertical interlocking allows for seamless variations of wall inclination and retains structural integrity. This particular retaining wall has a 5kPa loading and a water thank behind it.  Although well suited to terracing and creating flower beds, it can also provide a closed force wall effect which was a specification for this site.

These retaining walls were constructed using Remblok 30 Grey blocks.  Despite the significant height of this retaining wall construction was completed without any technical difficulties and within tight time constraints.   Remblok 30 was selected because of its strength and cost efficiency.

Some wall sections were designed and constructed against natural cut faces; here extension pieces were placed behind the ReMblok’s together with soil fill, to create mass and depth.

In other areas, as with our other sites, the bulk fill walls utilised were reinforced with high tenacity  polyester geofabrics, made from 100% recycled plastic – soft drink bottles, which were placed horizontally behind the retaining blocks for structural integrity.  Very much like steel reinforcing concrete, geofabrics are used to reinforce the bulk fill, which was compacted to the correct specification in layers not exceeding the block course heights.