METHOD FOR BLAST CRUSHING OF GROUNDS FOR EJECTION FOR EXTRACTION OF OBJECTS, LOADING CHAMBER AND ELONGATED DETONATING CHARGE (MODIFICATIONS) FOR REALIZATION OF THE METHOD Russian patent published in 2001 - IPC

FIELD: blasting operations, applicable for withdrawal of rescued object from the ground. SUBSTANCE: method consists in the following. An elongated detonating cord installed in the loading chamber made in the form of a ring is placed in the ground, with air gaps around the edges and in height of the ring, and initiated. The chamber is positioned in the ground above the rescued object horizontally at a distance from the rescued object determined from dependence H_p= f^*((H•D²-1,7•D33

)/(H•D)), where f-ground hardness coefficient equal to 2.0 to 4.0, D-maximum external dimensions of the rescued object, mm, D₃-diameter of loading chamber in its inner surface, mm, selected within 0.75-1.25 of the maximum external dimensions of the rescued object. The loading chamber and the rescued object are electrically connected, and the rescued object is brought out from the ground with a time delay equal to (10-350)•10^-3 sec. of the time of initiation of the elongated detonating charge. The loading chamber is made in the form of a sealed body in the form of a ring, and an alloy on the basis of iron is used as the body material. Made on the body is an assembly for receiving of electric signals, fastened in the assembly is the detonator with the gas conduit bush. The elongated detonating cord contains an explosive placed in an envelope in the form of a nitrocompound with an insufficient oxygen balance within 20-48% placed in an aluminium envelope made in the form of an open torus or in the form of a spiral. The spiral may be cylindrical and contain two turns, or tapered and contain three turns. EFFECT: extraction of rescued objects without deformation of the external envelope. 8 cl, 9 dwg