Assuming that the vibration waves emitted by successive detonations in the near by holes, each having an identical set of explosives, are identical each other, a proper delay between holes, which significantly reduces the peak particle velocity (PPV) at any point of interest, can be designed, based on the theory of superposition of waves. Blast vibrations were measured in situ in order to design an efficient production blasting in an open pit limestone quarry, where the pit floor is approaching an abandoned stope whose roof must be maintained stable to prevent the pit floor from caving in. A relationship between PPV at the measuring point and the distance to epicenter was considered. Also PPVs based on different criteria, i.e. PPV minimization and auto-correlation minimization, were compared. Finally, two dimensional FEM analysis, based on the data of the in situ blast vibration measurements, was performed to estimate the distribution of the PPVs around a particular target point.
香春太平洋セメント�蟾畚婢杙海砲�いて発破振動の現場計測を行ない，計測点における最大変位速度(PPV)と震源までの距離との関係を考察した。また，段発発破の際の最適な遅れ秒時を２種類の規準により求め，結果の比較を行なった。さらに，現場計測の結果に基づき2次元FEMモデルのパラメータを決定し，段発発破を含む発破振動の数値シミュレーションを行なった。段発発破に関しては，薬量が等しい各発破孔間に任意の遅れ秒時を設定した発破において，各孔から発生する振動波を同一なものと見なし，目的地点近傍の各節点の振動からPPVの分布を求めた。その結果，最適遅れ秒時を用いた段発発破による局地的振動制御の有効範囲を推定することが可能となった。