Responses of four rock mediums to contained nuclear explosions

Underground nuclear tests in tuff, alluvium, rock salt, and granite have yielded data essential to the evaluation of the effects of contained nuclear detonations. The data indicate that for these mediums the cavity radius is predictable within ±20 per cent without regard to the physical or chemical properties of the rock in the immediate shot environment. Properties of the chimney of broken rock resulting from collapse of the cavity, on the other hand, are found to be related to the physical properties of the rock and to preshot structural weaknesses within the rock.