关键词: 爆破, 开挖, 爆炸荷载, 动应力场, 数值模拟, LS-DYNA

Abstract:

Due to propagation of explosion wave and non-constant flow of blast-induced gas after the ejection of blast-hole blockage, the blasting load in column blast hole is non-uniform distributed in the axis direction. By using the dynamic finite element software LS-DYNA, the influence of the non-uniformity of the blast loading on the induced dynamic stresses is studied. The results show that blast-induced radial compression stress and circumferential tension stress are the largest at the section of blast-hole bottom and the duration is the longest, while the stresses at the section of blast-hole orifice are the smallest. It is also found that the circumferential stress is more affected by the non-uniformity of the blast loading. However, the affected stress field is only restricted in rock mass near the blast-hole and the stress difference is small; the computational stress results of non-uniform and uniform loading are the same in far area from the blast-hole.

Key words: blasting, excavation, blast loading, dynamic stress, numerical simulation, LS-DYNA