The High Court heard all nine had disrupted and obstructed the motorway in October ? after a judge made an order barring protests on the road in September. National Highways said the protesters had breached the injunction and were in contempt of court ? admitted by all of the protesters.
Two judges handed out the sentences after hearing speeches from the demonstrators, who said they formed human roadblocks to highlight "leaky homes".
But Lord Justice Dingemans said their actions had caused "very substantial" disruption.
Dr Diana Warner, 62, of Bristol, was jailed for two months. Dr Ben Buse, 36, from the same city, was given 30 days in prison.
Biff Whipster, 54, of Canterbury; Paul Sheeky, 46, of Warrington; Richard Ramsden, 75, of Halifax; Ruth Jarman, 58, of Hook, Hampshire; Steve Gower, 54, of Gloucester; Steven Pritchard, 62, of Radstock, Somerset, and Sue Parfitt, 79, of Bristol, got two-month suspended jail terms.
Parfitt said they were "glad" not to be jailed.