Gabion Boxes in Levee and River Bank Protection Construction,River Training Works,and Channels

This page outlines the steps for fabricating gabion boxes, including their placement, filling requirements, and measurement, all essential for bridge construction projects along riversides.

FABRICATION OF GABIONS:

1,Selection of materials and standards

Standard Dimensions for Gabion Boxes and Mattresses Used

Wire Materials:

Utilizing steel wire compliant with DIN EN 16120-2, and observing tolerance per DIN EN 10218-2 T1, the wire features a ZnAl coat (comprising 95% Zn and 5% Al) or a Galfan coating. The minimum coating thickness adheres to DIN EN 10244-2, accuracy class A.

2,Installation steps

Step 1: Stretching
Unfold and stretch the gabions on the ground, ensuring creases are properly positioned to form the box.

Step 2: Cutting
Execute any necessary cutting so that cut wire ends are at least 50 millimeters from the twisted joins. After stretching and cutting, lift the side and end panels, ensuring the tops are level. Bend any loose wire ends down into the gabion box.

Step 3: Fastening and Lacing
Before binding, securely fasten corners and shape the box. Attach the binding wire to a top corner by lacing between two meshes and twisting the wire three half turns. Lace the wire around the vertical selvedges, if applicable, and through each consecutive mesh, pulling tight before securing to the bottom corner with three half turns on an adjacent wire.

Step 4: Pre-filling Positioning of Gabion Boxes
Position and secure the diaphragm panels to the gabion sides as done with the corners. Place the empty box on a prepared area in its final position, lacing it to adjacent corners or sides of previously placed gabions along all adjoining edges. If additional gabion binding is required, reference will be made in drawings or specifications.

Placement of Gabion Boxes:

Orderly place the gabion boxes, maintaining a face of uncompleted work, and wire at least two rows of empty boxes together before filling the box closest to the completed work. Secure one end or side of the box to completed works or stakes in the ground, stretching and securing the opposite end in an approved manner before filling.

Filling Boxes:

For boxes of one meter in height or more, cross-tension each compartment at third points in the height with wires, tied securely around the mesh or selvedge wire. Fill the gabion wire boxes to 25-50 millimeters above their tops, stretching lids tight over the filling and wire down in continuous lacing, similar to the corners.

Measurement of Gabion Works:

Gabions should be constructed to specified lines and levels, including all necessary excavation, filling, compaction, and trimming. Quantity measurement, in cubic meters, will be based on the nominal external dimensions of constructed gabion baskets. For Reno mattresses, the unit of measurement is the cubic meter (m3).

Bank Protection Works:

Undertake bank protection works using gabions and mattresses only after the bank has been satisfactorily trimmed and compacted. Place the frontline of gabion works to break the river force and cause deposition, ensuring their tops are approximately 600 mm above the river's normal flow level unless otherwise directed.

We also provide chain link mesh fences intended to act as debris traps and placed as directed. Plant adequate cuttings for long-term protection under the Engineer's direction, ensuring the cuttings are of a type known to strongly grow in the area’s moist ground conditions.

Additionally, we supply piles as part of the protection requirements.

Main uses of Gabion for River Bank

Gabions are extensively used for river bank stabilization and protection, leveraging their robust and flexible design. Here are some of the primary uses:

1. Riverbank Stabilization:

• Preventing Erosion: Gabions protect the riverbanks from being eroded away by the flowing water.
• Vegetation Support: The stones within the gabions can provide an initial platform for vegetation to take root, further stabilizing the bank.

2. River Training:

• Guiding the River: Gabions can guide the river flow in a particular direction, protecting vulnerable areas.
• Weirs: Gabion weirs are used to manage water flow, enabling controlled distribution, especially during flooding.

3. Erosion Control:

• Check Dams: Small check dams made of gabions slow down the water flow, reducing erosion.
• Scour Protection: Placed at the base of a bridge or pier, gabions mitigate scouring caused by rapid water flow.

4. Construction of Levees:

• Flood Defense: Gabion levees serve as barriers against floodwaters, shielding inland areas.
• Wave Breaks: Along coasts, gabion levees break wave energy, protecting inland structures.

5. Building Channels:

• Drainage: Gabions are used to construct channels, directing water flow and preventing stagnation.
• Irrigation: In agricultural settings, gabion channels are instrumental in managing irrigation.

6. Wildlife Habitat:

• Fish Ponds: In certain conditions, gabions can create environments that support local fish populations.
• Bird Nesting: The rough surfaces and crevices in gabion structures provide nesting spots for birds.

7. Aesthetic and Recreational Applications:

• Parks: Integrated with landscaping, gabions add a natural aesthetic to parks alongside rivers.
• Walkways: Beside riverbanks, gabions are used to stabilize walkways, providing safe, scenic paths.

8. Protection of Structures:

• Bridge Protection: Gabions shield bridge abutments from erosive forces, ensuring structural stability.
• Infrastructure Defense: They protect other structures like sewage treatment plants located near riverbanks.

9. Water Quality Management:

• Filtering Runoff: Gabions trap silt and debris from runoff, playing a role in maintaining water quality.
• Preventing Siltation: Acting as barriers, they prevent excessive silt from accumulating in water bodies.

10. Creating Rest Areas:

• Seating: Gabion benches along the river provide rest areas for visitors.
• Viewpoints: Elevated gabion platforms may offer viewpoints for scenic observations of the river.

In summary, gabions serve multifunctional roles in river bank applications, providing not just structural protection and stabilization, but also enhancing ecological, recreational, and aesthetic aspects. Their flexibility, durability, and cost-effectiveness make them a popular choice for various environmental engineering and landscaping projects.