Research On The Relationship Between Explosion Properties And Rock Breaking Ability

The anisotropy of natural rock and the transient process of explosion in the condition of high temperature and high pressure transient process make rock blasting study difficulty very much, the blasting theory lag dramatically blasting technology and practice because of the great gap between theory and practice. Aimed at the actual problems of explosive rock breakage, it is an important theory and practical significance to research the relationship between the explosive performance and rock breakage, deeply understand the rock blasting process, enrich blasting theory of rock, and use explosives correctly and choice reasonably blasting parameters.In order to investigate the relationship between explosive performance and the ability of rock breakage, the cube concrete test blocks were prefabricated, which compressive strength was45MPa and20MPa respectively, blasting was done on the concrete test blocks with the different performance of explosives, blasting effect and blasting fragmentation were analyzed, at the same time, the explosion performance of several typical industrial explosives were measured, the blasting effect and explosive performance parameters (detonation velocity, work ability, brisance, etc) were compared. The results show as follows:(1) The theory calculation results of explosive detonation heat QV were obtained. The heat of detonation of emulsion explosive is3615kJ-kg-1, powdery emulsion explosive is3805kJ-kg-1, modified ANFO (ammonium nitrate fuel oil) is3741kJ-kg-1,2level coal mine permitted water glue is3066kJ-kg-1, high power3level coal mine permitted water glue is2883kJ-kg-1. The total energy Et measured underwater explosion and theoretical calculation value QV are basically the same. Emulsion explosive is3670kJ-kg-1, powdery emulsion explosive is3685kJ-kg-1, modified ANFO is3654kJ-kg-1,2level coal mine permitted water glue is3086kJ-kg-1, high power3level coal mine permitted water glue is2862kJ-kg-1.(2) If the diameter of the blast hole is20mm, the maximum detonation velocity of emulsion explosive D can reach4944m·s-1, powdery emulsion explosive can reach3830m·s-1, and the detonation velocity of modified ANFO,2level coal mine permitted water glue and high power3level coal mine permitted water glue is2809m·s-1,3122m·s-1,3125m·s-1respectively. (3) From the explosion effect analysis for concrete test block, which compressive strength is45MPa, it can be seen that rock breakage capacity of emulsion explosive is dominant, fragmentation size distributions after blasting are as follows:Modified ANFO> high power3level coal mine permitted water glue>2level coal mine permitted water glue>powdery emulsion explosive> emulsion explosive. In the blasting test of20MPa compressive strength of concrete test block, blasting effect of powdery emulsion explosive is better than others, remaining order of modified ammonium nitrate fuel oil, emulsion, level2coal mine water glue, high strength level3coal mine water glue. In the rock blasting crater experiment under frozen soil environment, Crater radius size is as follows:modified ammonium oil> powdery emulsion explosive>2level coal mine permitted water glue> emulsion explosive> high power3level coal mine permitted water glue.Data analysis shows that high elastic modulus, Poisson’s ratio of tight hard rock, and high detonation velocity, high density of explosives can guarantee a fair number of stress wave incoming rock, create initial cracks, so rock breakage effect is better; In the experiment of middle hard rock, the change of explosive energy influence on the blasting effect greatly. Meanwhile, the detonation velocity of explosive can ensure basically initial cracks emerge, high detonation velocity explosives would impact the fracture prematurely, make the energy lost, which goes against the extension of crushing fracture network; in the soft rock of large plastic deformation, most of the stress wave energy was consumed in cavity, and rock elastic modulus is low, so it is suitable to use high energy and low detonation velocity explosive.