Trails in Wet Areas (continued)

Geogrids (Figure 37) are made from polyethylene sheeting that is formed into very open grid–like configurations. Geogrids are good for reinforcement because they have high tensile strengths, and coarse aggregate can interlock into the grid structure. Geogrids are normally placed on top of a layer of geotextile to obtain separation from saturated soils in wet areas.

Figure 37—Geogrids are normally placed on top
of a layer of geotextile to obtain separation from
saturated soils in wet areas.

Concrete grid blocks are another technique for armoring switch–back turns or steeper slopes, especially on trails designed for motorized traffic.

Geocells (Figure 38) are usually made from polyethylene strips bonded to form a honeycomb structure. Each of the cells is filled with backfill and compacted. Geocells are good for reinforcement, reduce the amount of fill material required, and help hold the fill in place. Geocell usually has geotextile under it to provide separation from saturated soils. The grids need to be covered with soil so they will never be exposed. Exposed geocells present a substantial hazard to vehicles due to loss of traction.

Figure 38—Geocell usually has geotextile under
it to provide separation from saturated soils.

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