Underground Cable Pull Pit or Box Spacing

A two step simple process will provide you with the correct answer.

1) Consult the applicable regional/national electrical safety code

2) Visit the local electrical inspection office, show them your plans, make any changes they order, get their official stamp of approval on the plans

In the US, there is no "length" requirement, but there is a "bends" requirement.

The maximum conduit bend between pull boxes is 360 degrees, accorcing to the NEC, NFPA 70.

Otherwise, if it's a straight pull, have at it. We have pulled long straight runs with a pick-up truck.

You may want to calculate the required pulling tension using the cable manufacturer’s data, in your raceway, and then consult back with the cable manufacturer for maximum tension allowable. A lot depends on the actual cable construction, and what is the practical lowest friction you can achieve over the 80 meters. Consider that you may have a bend at either end while installing, where the pulling stress can be further concentrated.

The cables need to be a "rattly fit" in the ducts rather than a "sliding fit". From the description given it is impossible for the forum to assess the fit.

For those sorts of diameters, one of the challenges might be achieving the bends necessary at the ends of the run.

Cable-pulling is a refined art. It is better to appoint a specialised cable pulling firm to this task rather than undertaking it without the benefits of prior experience.

These links should provide all of the information needed to calculate the answer to your question:

Use this link to calculate percent fill capacity of the conduit:

http://conduitfillcalculator.com/

Use this for pulling tension:

https://www.iewc.com/resources/technical-guide/pulling-tensions

If the cable routing is straight [horizontal] and will be pulled using a basket grip then Tmax=450 kgf.

3*95+50 power cable weight=W=4.8 kg/m

f=0.8 lubricated dirty duct [friction factor]

Lmax=Tmax/1.1/f/W the maximum distance for one pulling [no initial force, no bends]

Lmax=450/1.1/0.8/4.8=106.5 m