静态爆破作用下石方静胀破裂的DDA模拟研究 postprint

Abstract: Applying the non-explosive expansion media is a useful method for rock fragmentation in the mountain area where the vibrations are strictly limited.In this paper,laboratory tests were conducted to determine the loading conditions of single hole expansions in concrete specimens using expansive chemical agents.By adopting the boundary conditions and the loading paths of the lab test,a DDA model was established.Under the constant expansion rate,the penetration rate began to increase at an increasing rate,eventually causing the complete splitting of the sample.It showed that the crack propagations could be subscribed into four stages,i.e.initial uniform deformation,micro-cracking around the hole,subsequently fracturing along the shortest resistance,and final splitting.The increase of tensile strengths in artificial joints would have resulted in the delay of splitting.In addition,the fixed surrounding boundary would increase the fragmentations of rock blocks adjacent to the expansion hole.At last,a multi-hole expansion problem was simulated to illustrate the effects of the boundary at the site.