The gabion walls along the road near Sabie in Mpumulanga are now complete, there are four walls in total with various lengths. The first retaining wall is 4 metres high and is used to retain the cutslope-embankment, reduce water velocities off the tailings slope and act as a rock catch wall for silt and rock/debris coming off the cut slope, thus preventing this material falling onto the roadway.
The second gabion retaining wall below the roadway (halfway up the fill slope) will prevent lateral movement of soils from next to and below the roadway. Thus reducing the risk of roadway settlement and failure, we assisted with the supply of gabion materials, geotextile and toolsets to site. When the project started, we assisted the contractor with the on-site gabion training during initial erections which resulted in the rapid erection of the gabion structures, as well as the learning of skills. This gabion project should be completed by end October 2009.
Please view the rock spoil photo below and note the reason that most gabion contractors allow for about 30% waste or fines in the rock costing calculation, as this finer material generally cannot be used inside the gabion container as the rock size is to small or consists predominently of finer material.
We suggest the use of gabion tool sets to improve gabion installations on sites, our gabion frames – shown in the photo below – allow for better basket shape once filled correctly. The baskets should be tensioned either horizontally or vertically before the filling process takes place, the tension direction is dependent on whether you have an external horizontal or vertical mesh direction. Please contact us for further explanation regarding this interesting concept. All gabion walls generally use a geotextile behind and below the wall to reduce fine soil leaching through the gabion wall.
P.S. A photo of our gabion tool set is shown under the news item drop down as well as our new gabion installation video.
Gabions are a common application in the world and we try to help wherever we can to show how easy they are to be installed on sites using a local unskilled labor force.
The director – Louis Cheyne is shown in one of the photo’s below..!!