Decoupling Effect on the Level of Blasting Vibration

발파진동의 크기에 마치는 디커플링효과의 연구

The pressure-time profile of the explosion gases can controlled for the use of cartridge explosive with two techniques known as Decoupling and spacing of the charges. Decoupling consists of a space between the explosive column and wall of the blast hole. Four different decoupling index 1.4, 1.8, 2.34, 3.0 are selected in this field study. The level of ground vibrations with each decoupling index was measured and the empirical particle velocity equation from these data was obtained. The condition of new cracks at blast hole are also examined. As the decoupling index is increased, the level of the blast vibration is decreased. But the cracks in rock masses are efficiently formed to remove the broken rock. The vibration constant associated with test sites is given as $K=1564.5(D.L)^{-1.3233}$ in terms of D.I.(decoupling index).