近接発破の雷管に及ぼす影響と考察
1970 年 86 巻 987 号 p. 425-430
詳細
1970 年 86 巻 987 号 p. 425-430
Through the present study about the blasting in a coal mine, the author found out the following results.
1) Under certain circumstances, the detonation of an explosive in a charge hole is apt to bring about missfires of the M.S.delay detonators in the nearby charge holes.
2) These missfires mentioned above can be considered to be due to the blasting conditions, such as the kind and the amount of explosives, kind of rocks and especially the line of least resistance.
3) The.author has claimed for a long time that the line of least resistance which is set in the blasting in a coal or a shale must be kept over 40cm for the prevention of blasting accidents and this author's opinion has been ascertained again to be right by the present experiments.
4) The delay time of the M. S. detonators in the adjacent chambers shows the tendency to become shorter with the influence of the stress wave caused by the detonation of an explosive in the nearby charge hole.
