3DMat installation Guide

ZhenLEM®-GeoMat and GeoMat R1, are three-dimensional erosion control mats manufactured from UV-stabilised synthetic fibres. ZhenLEM®-GeoMat R1 incorporates additional reinforcement within the polymer matrix, available with either double-twisted steel wire mesh or synthetic geogrids of various tensile strengths.

The products are supplied in roll form. Steel mesh reinforced ZhenLEM®-GeoMat R1 features one rough surface and one smooth surface. Normally, the smooth side is laid against the substrate to be protected; under special site conditions, the smooth side may be exposed outwards if required. Synthetic geogrid reinforced ZhenLEM®-GeoMat R1 retains the standard cuspated matrix profile of unreinforced ZhenLEM®-GeoMat.

Surface Preparation

1. Grade and lightly compact the slope to form an even surface, filling depressions as necessary.

2. Prepare a level anchorage bench and trench in firm subsoil around the perimeter of the installation area.

3. Leave the top 25–50 mm of topsoil loose to minimise soil voids and facilitate seed establishment on the embankment slope.

4. When applied as an erosion control mat, two seeding and fertilising options are recommended: apply seed and fertiliser directly onto the topsoil prior to laying ZhenLEM?GeoMat; or carry out hydroseeding after mat installation.

5. When used as turf reinforcement matting, topsoil and seed (or hydroseed) shall be placed after ZhenLEM®-GeoMat has been installed.

Tie-Down Trenching

1. A simple fold of the mat edge back into the slope is generally sufficient for perimeter anchorage.

2. For erodible soils, excavate a trench approximately 300 mm deep ?500 mm wide, set back at least 0.5 m from the slope crest. Anchor the mat along the base of the trench. Note: For reinforced mats, trench dimensions must be purpose-designed to achieve the required anchorage capacity.

3. Backfill and compact the soil to a smooth, even surface.

4. Initially lay the mat loosely over the soil surface to avoid soil pockets. Secure the mat into larger surface depressions with fixing pins to reduce voids between the mat and slope face.

Fixing

Steel fixing pins shall be used to secure ZhenLEM®-GeoMat R1 to the slope. Site trials shall be undertaken to confirm the optimal fixing method and spacing. For most applications, the following pin specifications are recommended:

· Unreinforced ZhenLEM® GeoMat: 4–8 mm diameter steel pins with asymmetric legs of 300 mm / 100 mm

· Reinforced ZhenLEM® GeoMat R1: 8 mm diameter steel pins with asymmetric legs of 300 mm / 100 mm

Fixing pin density shall be determined by the project engineer, subject to slope gradient, surface soil type, and anticipated shear stresses for hydraulic applications. The following is for general guidance only:

1. Space anchor pins at 1 m centres along the embankment slope crest and along the base of the anchor trench.

2. Under normal conditions (excluding perimeter fixings): one pin per 2 m?for ZhenLEM®-GeoMat; one pin per 1.5–1.7 m?for ZhenLEM®-GeoMat R1.

3. For slopes up to 1:1 (V:H) and channel linings: anchor pins spaced at 1 m perpendicular to the slope line, and staggered at 1.2 m intervals parallel to the slope line.

4. Slopes steeper than 1:1 (Vertical:Horizontal) require closer fixings, to comply with the project engineer’s recommendations.

5. Where steel mesh reinforced ZhenLEM®-GeoMat R1 is used together with soil nails for reinforced slopes, additional fixings may not be necessary. Secure ZhenLEM®-GeoMat R1 using anchor plates and nuts as specified for the project.

6. Drive fixing pins perpendicular to the mat (engaging the woven steel mesh of ZhenLEM®-GeoMat R1), flush with the soil surface to deliver the required pull-out resistance.

7. Adjacent panels of unreinforced ZhenLEM®-GeoMat and geogrid-reinforced ZhenLEM®-GeoMat R1 shall overlap by a minimum of 100 mm and be pinned through the overlap.

8. Adjacent panels of steel mesh reinforced ZhenLEM®-GeoMat R1 do not require overlapping. The integral steel wire mesh enables butt-joint connections between panels using lacing wire, fixing rings or fixing pins, selected according to site application.

For further documentation, technical guidance and project-specific support, please contact the Sales Department of Hebei Zhenlu Engineering Materials Co., Ltd.