PolyCell Geocells for Channel Lining & Rural Roads

PolyCell installation requires no specialist plant or equipment and is suitable for unskilled labour with competent supervision. The critical requirements are correct anchor trench excavation at all slope crests and toes, sufficient cell tensioning during panel expansion, correct infill drop height control during initial filling, and adequate concrete practice for concrete infill applications.

1. Site Preparation - Remove all vegetation, rocks, and obstructions from the slope or channel surface. Shape and compact the formation as required. For channel lining applications, excavate 300mm x 300mm anchor trenches at the top and bottom of the channel slopes. For slope protection applications, excavate anchor trenches at the crest and toe of the slope. Where a geotextile separation layer is required under the PolyCell - typically for channel lining over erodible subgrades - install and overlap the geotextile in the direction of flow before panel deployment.

2. Panel Deployment and Tensioning - Lay the first PolyCell panel in position and expand using the tension frame, pulling at 1m to 1.5m intervals across the long side of the panel using Y10 or Y12 steel pegs. Ensure cells are sufficiently tensioned so that the cell walls remain upright once vertical pressure is removed. Connect adjacent panels by vertically threading standard wire nails or clipping into existing pegs at corresponding cell positions. Where changes in direction occur, insert binding wire or builders twine centrally through the cell walls at the inflection point and tension and peg along the wire with hooked pegs.

3. Anchor Trench and Boundary Fixing - Place the leading edge of each panel into the prepared anchor trench at the crest and toe. Backfill and compact the trench. For channel applications, peg the straining wire along the top edge of the panel at both sides of the channel to maintain panel position under hydraulic load. Install under-scour protection at regular intervals on channel installations as specified by the engineer. Pegs used during tensioning can be removed after infilling is complete.

4. Concrete Infill - For channel lining and concrete road applications, infill from the crest of the slope to the toe. Limit the drop height of fresh concrete to a maximum of 1m to prevent cell collapse during initial placement. Once the initial platform of concrete is established, work the material into adjacent partially filled cells. Use temporary edge rails and a vibrating screed bar to accelerate finishing. Vibrate, float, and cure the concrete surface to the required finish using standard concrete practice. For dished road profiles, form the road cross-section to channel stormwater away from the carriageway surface.

5. Granular and Soil Infill - For slope protection with topsoil or granular infill, place the first batch of material with caution to prevent cell collapse. Once the initial platform is established, stockpile onto this base and work the material into adjacent partially filled cells. Limit drop height to 1m maximum. For vegetated slope applications, seed the topsoil infill immediately after filling and apply a temporary erosion control blanket or hydroseed mulch over the planted cells to protect germination until vegetation is established.