How did Sasuke survive the Tsuchikage's particle style? In the battle between Sasuke and the 5 kages at one point Onoki uses his particle style on Sasuke and Karin notes that his chakra has been completely eliminated, but then somehow Obito brings Sasuke back from his sharingan dimension and then suddenly he is alive again.

Has there ever been an explanation as to how Obito saved Sasuke here?
You've answered this one yourself - Obito intervened and teleported Sasuke to the Kamui dimension, thus preventing his death.