Rootlok - Geogrid reinforcement

Advice and variations when you are installing a Rootlok retaining wall with geogrids

To view the full installation guide please click here. 

Geogrid Reinforcement

Check your design drawing to ascertain whether geogrid is required and if so, which type - wrap around or non-wrap around. Design drawings will indicate what rows geogrid should be installed.

Geogrid standard

• Measure out and cut the geogrid into lengths as required in the design. The thicker edges on the two sides must be perpendicular to the wall face. The strength of the geogrid lies in the direction it is rolled – be sure to roll it toward the back of the wall, ensuring that the principal reinforcement direction is perpendicular to it (see Fig 10).

Fig 10. Geogrid placement.

• Ensure a minimum overlap of 300mm is between the layers of grid.
• The first layer should be no higher than top of the 1st course of Rootlok bags. lTop layer to be max 420mm (3 blocks) below finished ground level.
• Where a geogrid layer steps up/down one course, there should be a minimum overlap of 375mm (half a Rootlok bag width).
• Geogrid lengths from the higher sections should be used for intermediate wall heights.
• Tension must be applied to the geogrids before fill is placed over them.
• At least 100mm of backfill to be placed above grid before tracking plant on top
• Geogrid is to be placed below the plate ensuring the grid extends beyond the plate (see Fig 11).

Fig 11. Interlocking plate placement.

• Do not used damaged grid.

Geogrid wrap-around

This is when the geogrid is wrapped around the front of the wall (see Fig 12).

Fig 12. Geogrid wrap-around.

• Cut the geogrid to the required length, taking into consideration the base length, height of wrap and length of tail.
• Place geogrid layer as per standard method leaving enough length available to bring the grid up in front of the bags and to return into the system (see Fig 13).
• Lay bags rows as per standard method.
• After the bags have been laid on the layer of wrap around indicated in the drawing, wrap the geogrid over the top of the bags and onto the backfill. Achieve better tension by using a small whacker plate on the bags prior to wrapping. Use a small amount of fill to weigh the grid and keep it under tension whilst the rest of the backfill is poured for that layer. Compact as usual.
• Ensure geogrid is returned into the backfill as specified in the design drawings.