Geodude grabs the opponent, rises into the air, and throws them to the ground, or Geodude grabs the opponent, floats into the air and falls, spinning as it falls and throws the opponent to the ground before they both hit it.
Machop grabs the opponent and spins around in a circle. After a bit, Machop lets go and the opponent goes flying.
Primeape grabs the opponent's leg and head, jumps up and throws them to the ground.
Charizard grabs the opponent, flies into the sky, spins around, zooms back down, and tosses the opponent into the ground for more damage, using the momentum of the dive.
So the user grabs the opponent, rise to the air, and throws or rams to the ground
I don't think there are specific damage calculated in the anime