I recently built a 9'H x10'W x 10'L Pergola on a concrete slab. Each corner has a 6x6 pressure treated post and one of the post has started to twist on the bottom. The top has not been affected yet but I am worried it soon will. Any way of trying to straighten out the post. The post is anchored to the concrete but I believe the recommended 1 bolt anchor wasn't enough support. Please Help!

A 6x6 twisted, not bowed? Unusual.

No amount of bolting would have prevented. You will just have to replace it.

There are grades of pressure treated lumber.

Need ones that are structure rated.

Chuck