In this report we present a severe test of the effective stress and air-void porosity constitutive models by using them to simulate experiments in which small sale explosions were detonated in grout spheres. High quality reproducible particle velocity data were obtained from these experiments. We show that an effective stress law coupled with the irreversible collapse of air-filled porosity provide a very simple, straightforward explanation of this data. These results have served to reenforce our confidence in the validity of these models and their importance in determining seismic coupling. (Author).