How to build an access track across a field?

[Tophernose]

Hello everyone! I am looking to construct a 2 single tyre chalk track 300 meters across a field. Dimensions: 2750mm wide road, 900mm tyre tracks and a central 900mm grass verge. 300 mm deep with 200 mm hardcore on-top of a geotextile membrane and 100mm chalk or limestone consolidated in layers on top. I am looking at digging the full width trench and setting aside some soil to refill the central verge. The ground conditions currently in the field is a chalk sub-base with clay and flint deposits.

 My questions are;

1. Do I run the geotextile the full width of the trench, including central verge?

2. Do I fill the central verge with hardcore too, with soil / grass on-top?

3. How far do I need to take the hardcore sub-base beyond the outsides of the visible top chalk surface to avoid the track being pushed out horizontally?

 

Any advise would be greatly appreciated,

Many Thanks, Topher

[figgy]

It will be easier to just roll out full width geotextile and it wont harm the verge  you will only be growing grass.

[Tophernose]

2 hours ago, figgy said:

It will be easier to just roll out full width geotextile and it wont harm the verge  you will only be growing grass.

Thanks figgy, but the chalk is what's required from us by the national trust and planning, it is a cattle field and they don't want geo-grids. should have said this in my original explanation sorry.

[figgy]

if you don't want to use any textile, i would use large rock or bricks from demolition and roll them in to your trenches.