Selecting the right geocell height is one of those significant choices that have an imminent effect on load distribution, and the resultant road pavement and project’s performance for years to come. Some engineers are fretting about geocell material, or weld quality, or thickness – the geocell height is simply whatever height has the required capacity for confining and reinforcing.

At a different road project, the geocell height would be quite different. You may not want the same cellular confinement depth for light-duty parking as for a bona fide heavy mining haul road, or access road, over soft ground.

There are other implications as well of poor height selection! You could under-stabilise and waste material and drive the value up, or, alternatively, pavement failure could occur. Read on, for the essence of how geocell height affects road performance.

Geocell height

Is the depth of the cellular confinement structure achieved after installation of the geocell.

Common geocell heights are;

• 50 mm
• 75 mm
• 100 mm
• 150 mm
• 200 mm

As a general rule, the greater the geocell height, the greater the confining effect on the various infill materials, be it gravel, crushed stone, sand or soil.

Effectively a greater height does give a greater “quantity” of earth confinement (other things being equal) and, it should be said, more thorough lateral distribution of the loads going over the geocell will occur, which ,ceteris paribus, tends in favour of less rutting.

TheThe opposite is also true, lesser or lower cells do not confine as well, and thus lower load bearing capacity. Less confined infill aggregate would spread more under equally heavy applied load.

Of course less materials would be consumed with lesser geocell heights, and so cheaper to the project.

Why would it matter?

We’ve all seen and fought against the major rutted sections of road surfacing in the country where great traffic volumes or infrequent maintenance has caused a spreading out of aggregate layers to resist dynamic loads or at least redistribute them from a focused application in a singled out surface to more of a kind of relief system thus preventing the formation or rutting, and further propagation thereof through simple settlement and cracking.

A geocell on a ballast base, albeit a loose one, does provide that 3 dimensional confinement system which will stabilise the base………How tall the geocell is will determine how effectively the infill material is “locked in” and that in turn determines how effectively confinement is achieved, and what are the benefits therefrom.

Benefits of the Right Geocell Height

More load support

Deeper cells will transfer wheel loads across more area so even weak soils can accept more load without being damaged or rutted up.

Less aggregate “movement”

Better confinement relies less on how well packable base materials are.

More Stable Base

Under repeated traffic loads, the base material won’t so much migrate laterally when better confined.

Thin Lifting / Thinner Base

Not only is the whole thing just that much cheaper in transport as it doesn’t weigh as much, but a lighter weight plus a better design also translates to the demand being for thinner sizes of the aggregate as a whole.

Lifespan For Roads

No more muddy metalled road bases and driving on roads that simply don’t break down or that maintenance is carried out on, makes all the sense in the world and thus the norm.

Recommended geocell heights for what roads

There’s no one “best” type, and in deciding which to use it is simply a matter of expected traffic loads and configurations, soil characteristics, the use (or class/type) of road and the design of the pavement, and expected service life.

50 mm

Walkways generally, path ins some landscaping, a place the kids can ride their bikes on away from traffic, light ped areas.

Advantage:
Incredibly economical and quick and easy to install, materials not expensive to procure either.

Disadvantage:
Just not something you want compacted under heavy traffic, not really. Even more so maybe on reinforcing layers underneath.

Quite often not a road that vehicles drive and run on all the time.

75 mm

Residential driveways, parking lots, light duty access road.

Advantage:
Fairly moderate degree of confinement of the materials here associated with, so very economical. Fairly Good overall value.

Disadvantage:
No use for heavy traffic routes.

May well work, where traffic counts not so heavy and especially if soil present is a pretty strong one. It does very well in this case.

100mm

Municipal roads, temporary, construction type roads, all list of yard and storage used industrially, some quite easy access type roads in the rural more sort of way.

150 mm Geocell Height

Suitable for:
Heavy-duty roads; Container yards; Mining roads; Port pavements; Soft soil stabilization.

Advantages:
Efficient at confining; Good resistance to rutting; Significant bearing improvement.

This height would normally be chosen on soft subgrades devastated by full-size traffic and heavily-loaded axle loads in general.

200 mm Geocell Height

Typical for:
Very weak and soft ground; Heavy mining roads; Military Roads; High load industrial platforms.

Advantages:
Max confinement; Best stabilising ability; Very little settlement.

However, as 200 mm geocells are harder to lay and more costly, the use is confined to more demanding engineering environments.

How do my soil conditions affect how I choose height?

As a general rule, if the subgrade is weak choose a higher cell accordingly.

Strong Subgrade

If the soil is of reasonable bearing power then lower heights may suffice.

Typical choices:

• 75 mm
• 100 mm

Weak or Soft Soil

Soft clay, saturated soil, loose sand require strong confinement.

Typical choices:

• 150 mm
• 200 mm

Traffic Load and Height

Traffic volume and max axle load is another guideline.

Repeated Traffic of Heavy loads always implied deeper cellular confinement systems.

Do Higher Geocell always perform better?

Not necessarily!

Whilst taller heights do achieve increased confinement, a higher profile can be an incremental expense without providing you with the design parameters you require.

Points of reference for consideration choosing height;

• Overall cost of the project
• Quality of fill
• Site soil
• Pavement
• Traffic
• Ease of installation

For this type of work in general – road stabilization work, a geocell of 100 mm or 150 mm are recommended for most applications – it is these geocells that will provide the best performance versus cost to weight on the wheels of the next lane of traffic.

Textured Vs Smooth Geocells & Heights?

The profile surface texture can have an effect on performance:

Textured and Perforated Geocells

Advantages gains:

• Better hold onto infill material.
• Good drainage.
• Improved Confinement

Many cross applications for these products including road stabilization.

Non Perforated Geocells

Advantages gains:

• Good at holding back water and preventing the fine particles from passing through.

But, for 99% of the time that this geocell system is being deployed for roadbuilding where the ground is too soft to take the roadtraffic without remedial works damaging it the best choice of modern material is a textured perforated Geocell.

Weld Strength is Another Thing

You may have chosen the right height for your geocell, but if the welding is not to standard it all might as well be of no real use:

Using top notch ultrasonic welding will guarantee not only that the seam is tougher, but also a longer lasting system on the road, and a superior lifespan remaining for traffic load cycles.

This is a vital aspect on heavy duty roads when a great deal of serious loads will become uniformly distributed throughout the entire structure.

Common missteps in Selecting a geocell Height

Making Choice Based Just on Price

Products with a decreased height do convert to savings but a rather difficult and expensive situation for the person laying down the road!

Not Observing Site Soil

Look to a the deeper system where the soil isn’t up to par.

Opting for Designer & Engineer Overweight

That poorer lighter weight ultimately cost an arm and leg.

Not Thinking of Future Requirement of Traffic

You future requirement of traffic needs to be on the drawing board.

Conclusions

It’s not a part science to choose that one “best” geocell height for highways. You also put in the push of traffic rises, soils, pavement, and cost.

Broadly:

• 75mm “geocells” for light, rare traffic
• 100mm for lots of English roads
• 150mm for stabilising heavy-duty pavement
• 200mm for soft soils plus the most substantial loads.

With most road stabilisation, in most places, 100-150mm HDPE geocells are the ‘sweet spot’ for performance, service, and cost.

Choosing the right geocell will give you greater life with lesser maintenance and better stabilisation of the permanent pavement.

FAQ

What is the commonest geocell height for roads?

100mm geocell is amongst the commonest measures employed in road stabilisation, as it gives a wonderfully good compromise.

Is 150mm geocell greater than a 100mm?

150mm geocell makes stronger confinement, and is best designed for heavy traffic or soft soils, it’s not always necessary in a light-duty pavement.

Can geocells lessen the thickness ofroad base?

Yes, they assist the spreading of the load and the rubble is confined so the designer may often specify a lesser thickness aggregate base.

What geocell stands for soft earth roads?

The high strength textured and perforated HDPE geocells are generally specified that height 150 or 200mm.

How long do HDPE geocells last in our roads?

Good quality geocells last for true decades in road and protected permanent ways.

Are perforated geocells superior for roads?

Usually Yes, perforated geocells aid drainage and frictional effects for the infill grains, and is often employed than a blank geocell.