How do I keep ground squirrels from burrowing under my new paver patio

Trap and terminate. They multiple so fast if you don't.

http://neverpest.com/how-to-get-rid-of-ground-squirrels/

Squirrels do not like Blood Meal. If you sprinkle this at the entrance holes it may deter them from returning. You could also try household ammonia on a rag, in a small plastic bag, cut the corner and then install in the holes. The ammonia permeates the area and they scatter.

They also don't like hot pepper flakes. Scatter some of that around to deter them

Agree with Shoshana, they don't like hot pepper, you'll have to reapply after it rains.

Purchase a product called Repels All. It's a granulated, organic substance that irritates their nasal passages. I guarantee they won't come back after a couple of times. Sprinkle around the entire perimeter of your paver patio. Don't forget to cover your nose when sprinkling Repels All - I've gotten a bloody nose more than once and it always bothers me if I don't cover up. Reapply after a rain. It's important that you kill burrowing chippies because they'll continue to do damage. Revert to setting spring traps or putting poison peanuts down the hole.

Most any remedy needs to be continually repeated to maintain the area squirrel free unless you resort to an electronic type pest control product available online.

Maybe they are not trying to get in, but trying to get out?

Hi Deborah, hope this helps you. Soak plain red pepper flakes and a splash of dish liquid in a spray bottle of hot water and apply the scent to the pavers and along the edges. Repeat after rainfall

Concrete base and mortar joints.