Introduction

Geocell, sometimes also referred to as geocell confinement systems, have land in arrangements geocell might look like, between piling guns, tilting tillers, eco-friendly herbicides and laptop microscopes! They land on today’s wish list with the simple, practical idea of constructing a ‘cellular’ strengthenable layer. Made from HDPE, geocells arrive on site flattened and are expanded into the honeycomb structure shown, before being filled, typically with soil or gravel and, in extreme conditions, with concrete as an alternative! Instead of nowadays using very thick layers of aggregate or a rigid layer of materials, cellular confinement systems are being used in many applications to control the lateral movement of soil and prevent scour and erosion of excavation faces, especially on poor ground.

Key explanation

As the name implies, a geocell confines infill material in three dimensions within a series of interlinked cells. When pressure is exerted on the surface of the material, the load spreads to the sides of the cells, distributing the pressure and preventing further stress being pushed through into a weak subgrade.

Geocells bestow three observable benefits, or as explained:

• Confinement prevents the material from moving, either to the side or down into the weaker layers
• Load Distribution means the effect of the load on the softer material is spread out or moved sideways
• Stabilisation As a consequence of the first two, that means capability when loading is removed too, and also the long term performance

Textured or perforated geocells further enhance friction and drainage through the layer of fill, although a non-perforated geocell is available for cases where the control of water flow is more important than letting water through.

Applications / Use cases

Geocells are used in most industries as a means of ground stabilisation, protection and environmental restoration. The most common being:

1. Slope Protection

On embankments and steep slopes subject to rain fall and run of surface water. Cells can be vegetated with plants growing in the cells and there will be structural and ecological benefits derived from using them.

2. Erosion Control

In channels, flows on river banks and coasts, geocell systems protect against flow and wave action. They are filled with soil, sand or concrete depending on the severity of erosion.

3. Road Base Stabilization

For roads, highways and temporary access, geocells reinforce weak subgrades and mean the use of less aggregate. Common applications are:

• Construction Site access roads
• Rural/unpaved roads
• Parking areas and driveways

4. Load Support Systems

Under heavy loads like Container Yards, Industrial Areas or Logistics Parks, geocells will distribute loads reducing checking and rutting.

5. Retaining Walls

Geocell structures can also be stacked and filled to form flexible retaining walls. These walls which can be filled with non-structural materials are easier to install than concrete and will adjust to ground movement more readily.

6. Channel Protection / Drainage

In a drainage system geocells stabilize the channel bottom and sides and help to resist washouts but still allow the desired flow of water.

Comparison or Benefits

Generally speaking, there are several practical construction benefits to the use of geocells as opposed to traditional methods:

• Reduced material costs such as aggregate and fill
• A quicker installation considering geocells are lightweight
• Cost reduces as with lower transport and labor costs
• Flexibility in uneven terrain and steep slopes where cracking presents an issue
• Positive Environmental impacts, allowing vegetative cover naturally maintaining stability and reducing erosion

In many projects geocells can replace or at least supplement conventional pour and place concrete slabs or volumes of riprap or thick gravel layers.

How to Choose / Buy

As a buyer geocells are normally chosen according to your proposed application, but common considerations are:

• Cell Height. The taller the cell the more fill and load support for the heaviest application.
• Material Polyethylene type, with the most specified material being HDPE, although quality and density vary.
• Cell Surface. A sheathed textured geocell offers more friction and stability than other surfaces.
• Perforation. Creates opening within geocells for better drainage and also root penetration.
• Ultrasonic Welding. Generally ensuring the most durable strength of the geocell.

Purchase using best practice for your application; for heavy agenda host geocell qualitative more failure proofed high strength units; for opportunities for slope failure more oriented towards flutes and drainage etc;

Ask your intended supplier for the particulars of your application relative to the best specifications.