One of the defendants, a 24-year-old man, was sentenced to three months in jail and five months suspended.
He was found guilty of throwing a flaming oil drum at the police and setting fire to the shack in which he had been camping on the site, charges he denied, and kicking one soldier and spitting on another, which he admitted.
He was also banned from going to the area.
Another, a 30-year-old woman, was given a four-month suspended sentence relating to damage caused in the village of Bure, when protesters were forcibly removed from a "house of resistance" they had set up there.
She had refused to be represented by a lawyer or to defend herself before the court.
Another woman, who prosecutors said was part of a group who threw stones at a vehicle of workers sent to the site, was sentenced to three months in jail.
She had refused to give her identity, stand up in court or address it.
Nine other people are to face trial for related offences.