Tóm tắt:

Fragments in a blast is one of the factors to cause the unsafety for humans, equipments, and structures around the blasting areas. Thus, all standards and norms used for blasting safety refer to the radius of safety zone around the blast calculated by the largest distance of the fly fragments. However, recent researches are only applied for the fly fragments when blasting occurs on surface. In this paper, a method is proposed for determining the flying distance of fragments created by blasts in underwater environment. The equations of motion are derived for underwater fragments and then the impact resistance between an underwater blasting and the surface blasting are analyzed and compared to show the advantages of the method