This terraced and undulating round face Terraforce® retaining wall was installed by LFC Construction, to replace a collapsed wall on an estate in Herolds Bay, Garden Route, South Africa. The initial wall had been poorly installed by the previous builder, with no water management system, no drainage pipes and very poor compaction.
To avoid disappointments, read our advisory here.
The Herolds Bay project is a heavy-duty retaining wall which creates space for an access road with parking bays on the lower and top level, with three sets of 4×4 Step™ block staircases leading to the residential quarters situated in between the top deck and lower parking. The terraced retaining walls reach up to 10m in height and allow for a precast concrete seating arrangement and fountain, placed on a bed of Terracrete™ permeable pavers, in front of the guest rooms for private use.
Says Charl Johnson, LFC Construction: “The Terraforce L11 was installed on the rest of the Estate, so for consistency the same block size was chosen, along with the 4×4 Step block for the stairs. The walls were constructed using Y12 Rebar and concrete infill, on a concrete foundation, while the upper rows were filled with topsoil to allow for future planting. Geofabric tiebacks were installed every 1.8m and agricultural drains installed behind the Terraforce walls and stairs.
“The very steep upper terrace wall was raised to 5.1m, essentially creating extra space for three parking bays. Finally, lighting and irrigation, as well as balustrades and a straight edge curb for safety were installed. In total, 3500 L11 and 180 4×4 Step blocks and 25sqm of Terracrete grass pavers were used on site.
Johnson adds: “A challenging aspect of the project was the inaccessible nature of the project, with 470 cubic meters of backfill having to be compacted by hand – using 20L buckets – as no heavy machinery could get onto the site. Everything had to be done by hand, from offloading the blocks to filling them with concrete by bucket…”
Engineer: Fred Laker, Icos Engineering / Terrasafe
Main Contractor: LFC Construction
Blocks supplied by Terraforce licensed manufacturer: Mobicast