Abstract
A report is made in the present study of the measurements that were made of the stress waves and the accompanying particle velocities of rock particles in the cylindrical rock specimen caused by the detonator's attack and also by the explosive's attack. First the results were analyzed mainly from the standpoint of the compressibility of rock under impulsive high pressure, and some examples of the Hugoniot equation of state of rocks under comparatively low and high pressure obtained by authors' experiments are shown together with those obtained by others. It has been concluded in consequence of the above mentioned analysis that the compressibility of rock under comparatively low pressure, such as in the case of detonator's attack, has generally the linear relationship with pressure but the compressibility of rock under high pressure, such as in the case of explosive's attack, does not always have such linear relationship with pressure, but shows peculiar characteristics according to the individual physical properties of the rock in question.
Secondly, the maximum pressure produced at the boundary between explosive and rock by a collision of the detonation wave has been considered, and it has been shown how the magnitude of this maximum pressure can be affected by the dynamic characteristics of rock, especially by the compressibility of rock.
