Here you have a real world example of geogrid use.
We are in a wind farm in southern Spain, and thanks to previous experience with this technology the client decided to use a Tensar Triax geogrid TX160.
This is a triangular geogrid (the “old school” version was square). It seems that the triangular geometry guarantee a better distribution of the loads
The same geotextile has been used in many wind farms (more than 100) around the world, with several big project in Germany and UK where in some cases more than half a million square meters have been used. Often the soil was peat (turf), with a very low CBR (even less than 1).
The saving in crushed stone using a geogrid can be around 30% to 40%, so with a price around 2-3 €/sqm it is normally a cost effective solution.
When we opt for this solution we’ve had helpful feedback and hints from Tensar, as they can study the existing info and provide a design based on the soil conditions and the available materials. There are several models available with a different triangular size, so it is not easy to choose the right model.
We haven't had any problem during the first half of the civil works circulating with machinery and trucks, but when we started moving the narrow track crane on the internal roads between the pads significant damages appeared:
we deal with the geogrid and we are the factory,please send us the message to cooperate.
I think that the aggretgate used to built up those roads was wrong, You should use the well crushed and sorted material to allow the grains to be wedged in the "eyes" of the grid.