  We introduce a new interacting particles model with blocking and pushing
interactions. Particles evolve on the positive line jumping on their own
volition rightwards or leftwards according to geometric jumps with parameter q.
We show that the model involves a Pieri-type formula for the orthogonal group.
We prove that the two extreme cases - q=0 and q=1 - lead respectively to a
random tiling model studied by Borodin and Kuan and to a random matrix model.
