Advantages of Gabion Wall
Have you ever wondered when driving and you saw tones of stones or rocks filled in a basket of wire mesh? That structure is called the gabion wall.
You can see this structure near the stream, embankments or road.
What does the gabion wall do? And why use gabion wall? Well, one of the functions of gabion wall is for slope stability, which is to support and protect slope from erosion. Like other retaining structures, gabion wall has its advantages and limitations too.
- Strong base that provides strength from being drag away by river or stream.
- Reduce velocity of water as the energy dissipated by the rocks, thus reduce erosion.
- Its flexibility gives allowance to small ground movement.
- In most cases, as time goes, voids will be filled by vegetations and silt which will reinforce the structure and give extra strength.
- Depends on the availability of material and equipments, handling and transporting material is easy and this reduce the time of construction.
- Voids can be easily seen between the rocks which makes high permeability to the gabion wall. It allows water to flow through the structure which can maintain the water level in the ground (Groundwater level) to be low.
- Aesthetic impression is minimal. In a town area, where slope is supported by the gabion wall, the wire mesh basket can be seen and sometimes the rocks were surrounded by algae. However, there are some types of gabion wall that have high aesthetic impression and of course the cost will also be higher.
- In a high velocity of flow, wire mesh could damage due to high impact of large object.
The advantages and limitations depend on the site condition, availability of material and equipment/machine, and also manpower.
Site can be access by heavy machine. If it is near a river or stream, the depth of the river or stream should not exceed the depth that causes the machine to damage. The ground must also have a strength that is can support the weight of a heavy machine. For soft ground, if the cost is too high or if the volume is too large to remove the soft soil, then geosynthetic mattress might be required to increase the strength for the ground.
Availability of Material
Location of quarry, and place for manufacturing the wire mesh which allows ease of transportation to the site is a good indicator of utilizing gabion structure.
Equipments / Machine
The accessibility of the site condition (ease of transportation to the site), and the equipment/machines are available at that area.
Apart from operating the machines, most of the time filling and fastening the wire mesh basket is also done by hand.
There are more retaining structures other than gabion wall, such as reinforced concrete retaining wall and bored pile retaining wall. It requires a good decision making process to choose the best retaining structures. Analytical Hierarchy Process (AHP) is one of the decision making tool being utilized for decision making in this case.