Fixing patterns will vary depending on application type, slope length, slope grade, soil type, and annual rainfall. The fixing patterns shown above are based on slope length and slope grade. Increased fixing rates may be necessary depending on site conditions.
Peg types are shown in Figure 3.
MacPeg 200 mm and 300 mm in length to cater to different soil conditions are available from Zhengyang.
For detailed specific recommendations, contact us.

Slope Installation

• Prepare the site by removing large rocks, obstructions, or materials that may prevent the mat from making direct firm contact with the soil.
• Regrade the site as per the design. If topsoil has been removed, import topsoil, and grade out over the site.
• Seed the topsoil. Avoid over-compacting, which destroys the soil’s “crumb” structure. Anchor the mat at the top of the slope in a 300 mm x 300 mm trench. Backfill and compact the trench. (See Figure 5).
• Unroll the mat down the slope. Take care not to stretch the mat.
• Sprinkle 100 mm of soil onto the mat surface to weigh the matting down to mold closely to the soil profile.
• Fix the mat in position in accordance with the product fixing guide. Ensure there are sufficient pegs to maintain firm contact with the soil. Pegs on 100 mm overlaps should be at 0.5 m spacing. Placed up and down the joint, not across the joint.
• Ensure that the mat is well secure and protected from overland flow, floodwaters, and wind.
• Plant or seed as per the design with grasses, aquatic plants, rooted cuttings, seeded topsoil, or hydroseeding.
• Irrigate as required. Keep animal stock off until sustainable vegetation is established.

Channel Installation Considerations

• Dig a trench 300 mm deep across the channel at the downstream end of the project. Secure the mat in the trench, backfill, and compact the earth. Unroll the mat upstream. For larger channels with steeper slopes, it is preferable to place the mats perpendicular to the direction of flow.
• Secure the mat in intermittent trenches along the length of the channel. The mat also needs to be secured in a trench along the water’s edge and upstream when the lining is complete to prevent undermining.
• Parallel rolls should be overlapped 100-150 mm with the upstream section overlapping the downstream section.

Foundation preparation
FlexMesh is used as basal reinforcement in areas of poor subgrade support to improve and strengthen the founding soils (Figure 2). FlexMesh works best when founded on granular material. Leveling and clearing of the foundation is not a prerequisite before placement although a prepared surface facilitates installation. Depending on the application, the FlexMesh can be staked at prescribed intervals. Stone or coarse granular soil is then placed above and compacted. FlexMesh is deployed so that the curvature of the mesh is in contact with the foundation surface and the geotextile is below the mesh.

Unrolling
To facilitate installation, offload the FlexMesh as close to the work area as possible. FlexMesh is unrolled so that the mesh rolls off over the top of the roll rather than the bottom of the roll. This ensures that the FlexMesh is in contact with the foundation surface as much as possible. Care must be taken to ensure that during the unrolling phase, the geotextile is always situated beneath the mesh.

Fixing Procedure
Depending on the application, FlexMesh may be fixed with ground pegs at a maximum of 2 m centers if access for beachfront vehicles across an area with poor subgrade support is required(Figure 3). The suitability of the stake depends on the properties of the subgrade and the weight of the vehicle and its length, diameter, etc. would have to be verified beforehand. Where overlaps are required, connection rings (Spenax) may be used rather than the manual binding method.  Rings are to be spaced no further than 100 mm apart (Figure 10).
When used for basal reinforcement FlexMesh may not require much fixing other than at the corners and every 5 m to 10 m to facilitate the construction of the next layer.

Construction
For basal reinforcement, the FlexMesh should preferably be backfilled with a minimum 500 mm coarse stone layer. The interlocking stone supported by the mesh will provide the above layer with a firm platform. The thicker the stone layer, the stiffer the platform. The geotextile in all cases acts as a separation layer and prevents the stone layer from contamination by the poorer underlying subgrade. The coarse stone layer also serves as a drain alleviating excess poor water pressure during the consolidation and settlement phase.

Overlapping
Overlaps of 500 mm transversely and 300 mm longitudinally are recommended as a minimum. When overlapping, fixing the overlap using connecting rings (Figure 9) shall be carried out as per the previous procedure. When steel ring fasteners are used, the custom-made Zhengyang Manual Spenax Tool (Figure 11) is required and is available for hire.

Foundation preparation
Road Mesh is placed on a prepared surface of existing concrete or asphalt, newly placed hot mastic asphalt (HMA) or one recently milled. Road Mesh is deployed so that the curvature of the mesh is in contact with the road surface.

Unrolling
To facilitate installation, the Road Mesh rolls are off-loaded at 25 m or 50 m intervals. Once the roadbed or base layer has been carefully prepared, the Road Mesh is unrolled so that the mesh rolls off over the top of the roll rather than the bottom of the roll. (Figure 3). This ensures that the Road Mesh is in contact with the road surface as much as possible. Following deployment, a rubber-tired roller is used to remove the inherent curvature of the mesh. A minimum of two passes (four runs) are required by the roller to ensure that the Road Mesh is
in intimate contact with the road surface. It is important that the roller moves up and down the placed Road Mesh in straight runs (Figure 4). Any turning that is required shall occur off the placed roll. Turning on the roll will distort the Road Mesh.

Fixing Procedure
A minimum of the first 4 m of each roll mesh shall be securely fastened to the existing surface with nail anchors placed every square meter by a power-actuated device.
Two types of anchors are available:

• Hilti HPS Screws
• Hilti Nails

The type of anchor is chosen depending on the condition and type of the roadbed and base layer (Figures 5 & 6). Road Mesh placed on a granular base requires more of a screw-type anchor. When Road Mesh is placed on a much stiffer medium such as concrete, nail anchors would be more appropriate. The length of the anchor depends on the depth of the base layer and the pullout resistance generated. Anchors are supplied with clips that prevent the mesh from moving during the asphalting operation. For further advice in this regard, a nailing/anchor specialist should be consulted.

Overlapping
Overlaps of 300 mm transversely and 150 mm longitudinally are recommended as a minimum. When overlapping, it is necessary to shingle the panels to allow for easy placement of the asphalt. Only the end of the new roll should be fastened. Fixing of the overlap should be carried out as per the above procedure. When placing Road Mesh in thin overlays, special attention must be paid to the overlaps.

Construction

Depending on the condition and type of surface a tack coat or priming layer may be required (Figure 7)
This material may have several functions including sealing off various cracks that exist throughout the surface and providing an adhesive for the HMA to bond with the existing surface. When the mesh is placed within a stabilized layer at depth no pre-treatment is required.
When used within the bound HMA layers, Road Mesh is placed approximately 50 mm below the final surface. Depending on the function required, Road Mesh may be placed up to 300 mm below the final surface (Figure 8).
The remaining layers and the final HMA layer are rolled and compacted as per normal specifications (Figure 9).

 

Material Delivery
Double twist mesh rolls are supplied in roll form from the production facility in lengths of 25 m and 50 m. The roll dimension varies depending on the width and length of the roll required and whether the woven wire has the additional PVC coating. The rolls are individually strapped at the factory for easy handling and transporting.
Soil nails, anchors accessories, etc., and installation equipment in the form of power-actuated tools are not supplied by Zhengyang SA(Pty) Ltd and are to be sourced from approved suppliers.

Preparation and Placement
Placing double-twist mesh rolls is an operation generally performed on faces or slopes close to the vertical and sometimes of considerable height. Although the placing of the mesh may vary from site to site, the work may be reduced to four main phases.
1. Preparation of the surface to be blanketed (removal of loose rock particles, barring down).
2. Placing the netting over the surface to be protected by lifting the rolls to the top of the face and then unrolling them

3. Fixing the netting to the wall and tying them.
4. Final fastening of the net at the top, foot, and if necessary the face.
By far the more onerous phase of the project is phase 2, the lifting and placement of the netting over the surface of the slope.

The first method consists of transporting the rolls to the top of the face and after aligning, opening and fixing them on the upper edge, allowing them to unroll downhill. This method is used when there is some access road to the top and when obstacles such as telephone, power lines, and railway lines are at the foot of the hill.

The second method involves leaving the roll at the foot of the face, coupling a bar to it, and lifting it to the top of the face where it is to be fixed. A winch or crane would be required for this operation. Using cranes and winches may entail some operational constraints, for example, traffic delays and densities, and space restrictions when working on narrow roads.
To overcome some of the above constraints, helicopters have been used to speed up operations and for faces higher than 25 m, helicopters are the best solution.

Fixing Procedure
The distribution of the top anchorages must be calculated based on the maximum load that may occur at each anchorage, bearing in mind the breaking strain of the double-twist mesh. It is preferable to link the individual anchorages with a steel rope which must be tied to the mesh.
The following alternatives may be considered when small amounts
of debris collected at the toe:

• Leaving approximately 0.3 m open at the foot of the net to facilitate the removal of debris;
• Close the net at the foot to contain loose material.
  The bottom fixing must allow for periodic removal of accumulated debris after which the netting must be anchored again.

On the rock face, the sheets of netting must be securely and continuously laced together using a binding wire of diameter equal to or greater than the wire used for the manufacture of the mesh. Alternatively, metal stakes of various sizes can be used.
When necessary, the sheets of netting should be close together to prevent fragments of rock from rolling off. In addition, suitable anchorages must be provided at the rate of one anchor every 15 to 30 ㎡ of covered area.

Material Delivery
Sack Gabions are manufactured with all components mechanically connected at the production facility. All Sack Gabions are supplied in the collapsed form, folded and bundled. The bundles are compressed and strapped together at the factory for easy shipping and handling. Lacing wire is supplied in coils. Ring fasteners(Figure 5) are shipped in boxes that must be stored in a dry environment.

Assembly
The folded Sack Gabion units shall be taken out from the bundle and placed on a hard flat surface. They shall be opened, unfolded, and pressed to their original shape ready for assembly.
Foundation preparation
The foundation on which the Sack Gabions are to be placed need not be leveled and graded as Sack Gabions are used to provide a firm platform in areas where poor founding conditions exist or in areas where founding occurs in the wet. Appropriate measures shall be taken for the separation of the foundation layer from the rock-filled Sack Gabion by the project specifications (geotextile, drain works, etc.).Geotextiles required to be installed behind or underneath the Sack Gabion structures shall comply with the requirements of the project specification.

Lacing
Sack Gabions are assembled by rolling the mesh panel into a cylindrical shape and overlapping the selvedged edges. By pulling and tightening the lateral spiral wire, the edges are secured. Excess spiral wire shall be secured around the selvage wire by looping and twisting the wire around itself. Once the longitudinal overlap is secured, the one end of the cylinder can be laced closed. This is accomplished by pulling the two ends of the bottom spiral tightly together and securing by again looping and twisting the wire around itself (Figure 1). Care shall be taken to avoid damaging the wire coating. The remaining end of the cylinder is left open to allow the Sack Gabion to be filled with suitable stone.

Installation and Filling
Rocks for Sack Gabions may be produced by any suitable quarrying method and by the use of any device that yields the required sizes within the gradation limits chosen. Rocks shall be hard, angular to round, durable, and of such quality that they shall not disintegrate on exposure to water or weathering during the life of the structure. Rocks shall range between 100 mm and 200 mm. The range in sizes may allow for a variation of 5% oversize and/or 5% undersize rock, provided it is not placed on the exposed surface. In all cases, the oversize rock shall not be larger than 250 mm, and the undersized rock shall not be smaller than 80 mm.
Rock shall be placed from the open end of the cylindrical-shaped gabion. Once the Sack Gabion has been filled satisfactorily, the ends of the top spiral wire are pulled tight, twisted, and looped onto itself. Care shall be taken when placing the stone to avoid damaging the wire coating. Hand manipulation of the rock may be necessary to minimize voids and achieve a maximum density of the rock in the Sack Gabion.

Placement
To facilitate placement, Sack Gabions can be placed individually or in pairs, provided they are laced together. When lifting SackGabions, care should be taken to lift the Sack Gabion by the thicker overlapped selvage wires (Figure 3).

Material Delivery

Assembly
The folded units shall be taken out from the bundle and placed on
a hard flat surface. Green Terramesh units shall be opened,
unfolded and pressed to their original shape. When the units are unfolded for assembly, they will have one or two shipping folds. They can be removed by placing the fold over a board and walking along the sides.

Fixing Procedure
When using lacing wire, cut off a piece of wire approximately 1.5 times the length of the edge to be tied. The maximum length of the edge to be tied at one time shall not exceed 1 m. Longer edges shall be joined by several lengths of wire. Lacing wires shall be secured around the selvedge wire or heavier edge wire, where present, by looping and twisting the lacing wire around itself. Proceed tying with alternate double and single loops (Figure 3). Double loops shall be made at intervals not greater than 300 mm. All panels shall be pulled tightly together during the tying operation. Pliers (Figure 5) may be used to create tight joints. The other end of the lacing wire shall be secured by looping and twisting the wire around itself. When using lacing wire to assemble the units care should be taken to avoid damaging the wire coating. When steel ring fasteners are used, the custom-made Maccaferri Manual Spenax Tool (Figure 5) is required and available for hire. Rings shall be installed at the top and the bottom connections of the end and centre diaphragms and then a maximum spacing of 100 mm along all edges shall be used. Connect with ring fasteners between adjacent units. Connections made along the panel edges assure a flat surface for fill placement.

Foundation Preparation
The foundation on which the Green Terramesh units are to be placed shall be level and graded to the elevations as shown on the project construction drawings, and free of surface irregularities, loose material and vegetation by the project specifications.

Installation, Filling and Soil Compaction
After the foundation has been prepared, the pre-assembled Green Terramesh™M units shall be placed in position empty, and tied or fastened to adjacent units along all edges to form a continuously connected, monolithic structural unit. Units shall be placed in position according to the required slope angle. Triangular steel brackets shall be rotated and securely attached to the bottom of the main unit using conventional fastening tools(Figure 5) (lacing wire or rings). The erosion control blanket of each unit shall overlap for 100 mm with the adjacent unit blanket on the side in a manner to ensure that the vegetative soil behind will not be exposed at any time. Care shall be taken when placing the soil to avoid damage to the wire coating. After a layer of soil has been placed, sufficient hand shovelling shall be performed to achieve a uniform top surface before soil compaction is performed. Vegetative soil is placed behind the facing for about 0.5 to 0.6m.
Soil compaction within 2 m of the face should be carefully performed with a walk-behind compactor to prevent any slope distortion or bulging of the facing unit.

Place soil fill in approximately 300 mm lifts and compact it to the required level. Mechanically stabilised earth structures shall be made of good quality, free draining, granular and/or selected fill. The recommended soil gradation is in the range of 0,02 mm to 6 mm, or as indicated in the project specifications. Soils outside of this range may be suitable, providing they have been approved by a geotechnical engineer.

Compaction shall be performed to 95% of Standard Proctor, by use of conventional compaction equipment. The number of compaction and vegetative soil layers will be as such to achieve the required vertical spacing between the Green Terramesh units, according to the project specifications. Once the soil layers after compaction have achieved the top of the Green Terramesh unit, the top end is folded and securely stapled to the soil. Care shall be taken to ensure that all adjacent units (above, underneath and sideways)will be connected along the face at the contact edges.
The top return portion of the last unit on top of the structure shall be buried approximately 300 mm beneath the soil surface.

Hydroseed or plant, if needed, using a native species increases the chance of survival. Irrigation may be necessary in drier climates/seasons.

Material Delivery
Terramesh System units are supplied in a collapsed form, folded and bundled. The bundles are compressed and strapped together at the factory for easy shipping and handling. Each bundle is labeled with a tag indicating the sizes of the units contained. Lacing wire is supplied in coils. Ring fasteners (Figure 5) are shipped in boxes and should be stored in a dry environment.

Assembly
To assemble the Terramesh System units, follow these steps:
1. Remove the folded units from the bundle and place them on a hard flat surface.
2. Open and unfold the Terramesh System units, pressing them out to their original shape.
3. Lift the front, back, and end panels to a vertical position.
4. Fasten the panels together by firmly wrapping the projecting heavier gauge selvedge wire around the selvedge or edge wire of the intersecting panel or back panel.
5. Lift the inner diaphragm panels into a vertical position and secure them in the same manner.
6. Tie or fasten all edges of the diaphragm and back panels to the front and back of the facing section (Figure 1).

Fixing Procedure
When using lacing wire, follow these steps:
1. Cut off a piece of wire approximately 1.5 times the length of the edge to be tied.
2. The maximum length of the edge to be tied at one time should not exceed 1 meter. For longer edges, join several lengths of wire.
3. Secure the lacing wires around the selvedge wire or heavier edge wire by looping and twisting the lacing wire around itself.
4. Proceed tying with alternate double and single loops (Figure 4). Double loops should be made at intervals not greater than 300 mm.

5. Pull all panels tightly together during the tying operation. Pliers (Figure 6) may be used to create tight joints.
6. Secure the other end of the lacing wire by looping and twisting it around itself.
7. When using lacing wire, be careful to avoid damaging the wire coating.

When steel ring fasteners are used, follow these steps:
1. Use the custom-made Maccaferri Manual Spenax Tool (Figure 6), which is required for the installation of ring fasteners. The tool is available for hire.
2. Install rings at the top and bottom connections of the end and center diaphragms, with a maximum spacing of 100 mm along all edges.
3. Connect adjacent units with ring fasteners.
4. Connections made along the panel edges ensure a flat surface for fill placement.

Foundation Preparation
Before placing the Terramesh System units, prepare the foundation as follows:
1. The foundation should be level and graded according to the project construction drawings.
2. The foundation should be free of surface irregularities, loose material, and vegetation, as specified in the project specifications.
3. Take appropriate measures for filtering and drainage of the foundation, such as using filter cloth and drain works.
4. Geotextiles required to be installed behind the units should comply with the requirements for subsurface drainage applications.

Installation, Filling, and Soil Compaction
After the foundation has been prepared, follow these steps:
1. Place the pre-assembled Terramesh System units in position empty and tie or fasten them to adjacent units along all edges to form a continuously connected, monolithic structural unit.
2. Use rocks for the gabion facing section, which may be produced by any suitable quarrying method and within the chosen gradation limits.
3. The rocks should be hard, angular to round, durable, and capable of withstanding exposure to water and weathering.
4. The size of the rocks should range between 100 mm and 200 mm, with a variation allowance of 5% oversize and/or undersize rock.
5. Place rocks in 300 mm lifts for 1 m high Terramesh System units, and 250 mm for 0.5 m high units.
6. The fill layer should not exceed 300 mm higher than any adjoining cell, and care should be taken to avoid damaging the wire coating.
7. After placing a layer of rock in the cell, perform sufficient hand manipulation of the rock to minimize voids and achieve maximum density.
8. Hand place rocks in exposed vertical faces to reduce voids in the outer face.
9. Install stiffeners or internal cross ties, connecting the front and back faces of any supported or exposed face at the vertical third points for a 1 m high unit, as the cell is being filled.
10. Overfill the gabion facing section of the Terramesh System by approximately 25 to 40 mm to allow for natural settlement.
11. Smoothly level the top surface, minimizing voids, and ensure easy accessibility of the diaphragm tops for connecting.

Closing
To close the Terramesh System, follow these steps:
1. After leveling the rocks and minimizing voids, fold the lid down and pull the edges of the panels together.
2. Use an appropriate closing tool (Figure 6) or lid closer to lightly stretch and bring the mesh panel pieces together. Take care not to deform the mesh or damage the wire coating.
3. Wrap the projecting selvedge wire of the lid two complete turns around the selvedge wire or edge wire on the sides.
4. Tightly tie the lid along all edges, ends, and tops of diaphragms. Adjacent lids can be tied or attached simultaneously.
5. Turn all projecting sharp ends of wire inward on the completed gabion structure.

Backfill Structural Embankment
Before starting this operation, place a geotextile filter at the facing section and backfill interface. The geotextile should have a 0.3 m return at both top and bottom.
1. Carefully compact the soil fill within 1 m of the face using a walk-behind compactor to prevent distortions in the wall or slope face.
2. Place the soil fill in approximately 150 mm lifts and compact it to the required level.
3. Mechanically stabilized earth structures should be made of good quality, free-draining, granular, and/or selected fill.
4. The recommended soil gradation is in the range of 0.02 mm to 6 mm, or as indicated by the project construction drawing.
5. Compaction should be performed to 95% of Mod AASHTO using conventional compaction equipment.

Assembly
The folded units shall be taken out from the bundle and placed on a hard flat surface. JOESCO mattresses shall be opened, unfolded, and pressed out to their original shape. Front, back, and side panels as well as the double diaphragms shall be lifted to a vertical position to form an open box shape. End flaps shall be folded and appropriately overlapped before securing (Figure 1). All edges of the double diaphragms and end panels should be securely tied or fastened to the front, back, and sides of the mattress.
The mattresses should be assembled individually, by erecting the sides, ends, and diaphragms, ensuring that all creases are in the correct position and the tops of all sides are level.

Fastening Procedure
Lacing the lid of the JOESCO to the rest of the base and connecting subsequent JOESCO mattresses together can be undertaken using either lacing wire or ring fasteners.
Ring fasteners shall be installed at a maximum spacing of 100 mm apart (Figure 2). When steel ring fasteners are used, the custom-made Maccaferri Manual Spenax Tool (Figure 6) is required and is available for hire.

When using lacing wire, cut a sufficient length of wire and first loop and twist the lacing wire to the wire mesh. Proceed tying with alternate double and single loops through every mesh opening approximately every 100 mm, pulling each loop tight and finally securing the end of the lacing wire to the wire mesh by looping and/or twisting (Figure 2). The use of Pliers (Figure 6) to aid the assembly and wiring of the units using the binding wire supplied with the JOESCO mattresses is normally recommended.

Foundation Preparation
The foundation on which the Qiashi mattresses are to be placed shall be leveled and graded to the elevations as shown on the project construction drawings and free of surface irregularities, loose material, and vegetation in accordance with the project specifications. Appropriate measures shall be taken for filtering and drainage of the foundation, as per the project specifications(geotextiles, drain works, etc.). Geotextiles required to be installed behind or underneath the JOESCO mattress unit shall comply with the requirements for subsurface drainage applications.

Installation and Filling
After assembly, the JOESCO mattresses shall be placed in their proper location and securely attached to the adjacent ones. For structural integrity, all adjoining empty units should be connected by means of lacing wire or ring fasteners along all edges of their contact surfaces, in order to form a continuously connected, monolithic structural unit. On slopes, the JOESCO mattress shall be laid with a width perpendicular to the slope, except for very small ditches. Where JOESCO mattresses are to be placed on steep slopes, the units shall be secured by hardwood pegs driven into the ground just below the upper-end panel, at 2m centers, or as specified in the project requirements. Mattresses shall be placed and securely attached whilst empty. Mattresses can conform to bends up to a radius of 18 m to 21 m without alterations, and should be placed to the required curvature prior to filling. Mattresses may be cut to form curves or bevels.
Rocks for mattresses may be produced by any suitable quarrying method and by the use of any device that yields the required sizes within the gradation limits chosen. Rocks shall be hard, angular to round, durable, and of such quality that they shall not disintegrate on exposure to water or weathering during the life of the structure. Rocks shall range between 80 mm and 150 mm. The range in sizes may allow for a variation of 5% oversize and/or 5% undersize rock, provided it is not placed on the exposed surface. In all cases, any oversized rock for JOESCO mattresses shall allow for the placement of a minimum of two layers of mixed rock sizes, dependent upon the height of the JOESCO mattress. Care shall be taken when placing the stone to avoid damaging the wire coating. After a layer of rock has been placed in the cell, sufficient hand manipulation of the rock shall be performed to minimize voids and achieve a maximum density of the rock in the units. Start at the bottom if on a slope. Filling shall be done unit by unit, but several units should be ready for filling at any one time. Ensure that the diaphragm tops are easily accessible for connecting.

Closing
To allow for settlement, level off the fill 25 mm above the top of the mesh. In aprons downstream of weirs and similar places where water will fall directly on the JOESCO gabion mattresses, install additional bracing wires vertically between the top and bottom mesh taking care not to damage the geotextile. Also, a 50mm to 75mm 15MPa concrete cap is recommended. Make sure to keep the top edge of the diaphragms exposed. Lay the lid down and pull the edges of the panels to be connected, where necessary, using the appropriate tool as a lid closer. The lids must be tightly laced along all edges, ends, and double diaphragms in the same manner as described for assembling. Adjacent lids may be securely attached simultaneously.
Securely attach the lids to the ends of the JOESCO mattresses and then to the sides and diaphragms using alternate double and single loops, or steel ring fasteners. Adjacent lids can be securely attached in one operation.
In cases where a number of adjacent bases are to be covered at one time, rolls of mesh can be used in place of unit-size lids.

Assembly
The folded units shall be taken out from the bundle and placed on a hard flat surface. Gabions shall be opened, unfolded pressed out to their original shape. Front, back, and end panels shall be lifted to a vertical position to form an open box and lic(Figure 1).

Panels shall be fastened together with the projecting heavier gauge selvage wire by firmly wrapping the selvage wire around the selvage or edge wire of the intersecting panel or back panel (Figure 2).

Inner diaphragm panels shall be lifted into a vertical position and secured in the same manner to the front and back of the gabion (Figure 3)

Fixing Procedure
When using lacing wire, cut off a length of wire approximately 1.5 times the length of the edge to be tied. The maximum length of the edge to be tied at one time shall not exceed 1 m. Longeledges shall be joined by several lengths of wire. Lacing wires are secured around the selvage wire or heavier edge wire, where present, by looping and twisting the lacing wire around itself. Proceed tying with alternate double and single loops (Figure 4). Double loops shall be made at intervals not greater than 300 mm. All panels shall be pulled tightly together during the tying operation. Pliers (Figure 10) may be used to create tight The other end of the lacing wire shall be secured by looping and twisting the wire around itself. When using lacing wire to assemble the units, care should be taken to avoid damaging the wire coating. When steel ring fasteners are used, the custom-made Zhengyang Manual Spenax Tool (Figure 10) is required and is available for hire. Rings shall be installed at the top and the bottom connections of the end and center diaphragms and then a maximum spacing of 100 mm along all edges shall be used (Figure 4).

Foundation preparation
The foundation on which the gabions are to be placed shall be level and graded to the elevations as shown on the project drawings, and free of surface irregularities, loose material, and vegetation by the project specifications appropriate measures must be taken for drainage around the foundation, as per the project specifications (geotextile, frameworks, etc.). Geotextiles installed behind gabion structures shall comply with the requirements for subsurface drainage applications.

Installation and Filling
After the foundation has been prepared, the pre-assembled gabions shall be placed in position empty, and tied or fastened adjacent gabion units along all edges to be continuously connected, the monolithic structural unit (Figure Rocks for the gabions may be produced by any suitable quarrying method, and by the use of any device that yields the required sizes within the gradation limits chosen. Rocks shall be hard, angular round, durable, and of such quality that they shall not disintegrate on exposure to water or weathering during the life of the structure. Rocks shall range between 100 mm and 200 mm. The range in sizes may allow for a variation of 5% oversize and/or 5% undersize rock, provided it is not placed on the exposed surface. ln all cases oversize rock shall not be larger than 250 mm, and the undersized rock shall not be smaller than 50 mm. Rock shall be placed in 300 mm lifts for 1 m high gabion units, and 250 mm for for0,5 m high units. The fill layer shall never be more than 300 mm higher than any adjoining cell (Figure 7).

Care shall be taken when placing the stone to ensure that the PVC coating of the wire is not damaged. After a layer of rock has been placed in the cell sufficient hand manipulation of the rock shall be performed to minimize voids and achieve a maximum density of the rock in the gabion. The rock in exposed vertical faces shall be hand-placed to reduce voids in the outer face. Stiffeners or internal cross ties shall be installed connecting the front and back faces of any supported or exposed face at the vertical third points for a 1 m high gabion unit, as the cell is being filled (Figure 5).

Gabion units installed at the wall ends, having two exposed sides, shall also include a set of cross ties installed perpendicularly to the lateral exposed face. For m-high baskets when used as revetment, stiffeners or internacross connections are not required. When more than one vertical layer of gabions is installed, units shall be overfilled to approximately 25 to 40 mm to allow for natural settlement. The top surface shall be smoothly leveled, minimizing voids. Ensure that diaphragm tops are easily accessible for connecting.

Closing
After the rock has been leveled and the voids minimized, fold the lid down and pull the edges of the panels together. lt should require alight stretching using an appropriate closing tool (Figure 10) or a lid closer to bring the two gabion pieces together. Care shall be taken that the mesh is not deformed or the coating on the wire is damaged. The projecting selvage wire of the lid shall be wrapped in two complete turns around the selvage wire or edge wire on the sides. The lid shall be tightly tied along all edges, ends, and tops of diaphragms. Adjacent lids may be tied or attached simultaneously. All projecting sharp ends of wire shall be turned in on the completed gabion structure.