Patent ID: 8671814

Claim:
A blast treatment method for performing blast treatment of a treatment subject including a bursting charge and a shell containing the bursting charge, the blast treatment method comprising: an inside explosive disposing step of disposing an inside explosive for blasting the treatment subject around the treatment subject; an outside explosive disposing step of disposing an outside explosive having a detonation velocity greater than that of the inside explosive, at a position outside the inside explosive; and a blast step of initiating the outside explosive using an initiation device, and initiating the inside explosive by detonation of the outside explosive, thereby performing blast treatment of the treatment subject by detonation of the inside explosive, wherein the outside explosive disposing step includes an arrangement step of arranging more than two cord shaped explosive members being spaced at intervals about the circumference of the treatment subject, wherein all of said intervals spacing all of said cord shaped explosive members are equal to one another, the cord shaped explosive members each containing the outside explosive and each having a shape extending in a predetermined direction at positions outside the inside explosive so that a detonation propagation velocity in the predetermined direction of the inside explosive initiated by the outside explosive is greater than a detonation propagation velocity in the predetermined direction of the inside explosive; and wherein, in the blast step, the outside explosives contained in the cord shaped explosive members are simultaneously detonated, and the detonation of each of the outside explosives is propagated in the predetermined direction.