I did not install the woodwork or posts but they are elevated on galvanized pieces that manufactured for this purpose. They anchor into the concrete.

Those brackets raise/separate the wood from the surface just enough to help prevent the wood from sitting in water at the base/rotting. (that gray colored part is from water). They should be sealed with a water seal product at least around the base. You don't need to change the posts - a little beefing up at the base would also make them look more 'grounded' to their base. The stone porch and those railings are very nice.