We designed and supplied a 270m long and 9m high reinforced soil structure
A retaining wall was needed within the improvement works to the main road P728 in the Umgababa area, KwaZulu-Natal Province. We designed and supplied a Terramesh System solution to support the improved highway for a surcharge load of 12kN/m². Our geogrid ParaGrid was used for primary soil reinforcement. This solution proved to be easy-to-install and cost-effective and helped create employment with the use of unskilled labor.
Umgababa is a rural coastal community to the South of Durban, in the Kwa-Zulu Natal Province of South Africa. It is becoming increasingly popular for tourists as investment into this beautiful area is increasing. The eThekwini Municipality required improvements to the main road P728 which was being upgraded. A significant 270m long and 9m high retaining wall was required to support the improved highway, through the hilly terrain in the Umgababa area.
Various solutions were considered and we were approached by project engineer, Simani Consulting to provide design, supply and construction support. Although the ground to be retained was of good quality and there were no phreatic surfaces within the vicinity of the wall, the presence of slopes above and at the foot of the wall placed an emphasis on the overall stability of the structure. Loads of 12kN/m² needed to be considered as the highway live load on top of the structure.
We proposed a Terramesh System from 3m to 9m high, from a depth of up to 2m. On the taller reinforced soil structures and where the geotechnical forces are far greater, the Terramesh units were reinforced using our unique geogrid, ParaGrid.
The solution was designed using our MacSTARS mechanically stabilized earth wall software.
The selection of the Terramesh and ParaGrid hybrid solution was not only based upon technical performance; it offered numerous other benefits for this project.
- Due to the remote location of the project site, Terramesh offered the advantage of being easily transported and stored on site
- Easy to install – The assembly and installation of the Terramesh units requires minimal skilled labour, thereby it supports the South African government strategy of job creation within the Expanded Public Works Programme (EPWP)
- Cost effective: Terramesh requires significantly less rock fill than other solutions, including gabions
- The ParaGrid geogrid can be used with most types of backfills, including marginal fills. This often enables the reuse of site-won materials as structural backfill, which reduces the amount of imported materials, saving project cost and time
- Terramesh System is a flexible structure which is able to withstand the loads and vibrations that may be present during and after construction of the road
For more information, please download our case history.