Emulsion Explosives In Underwater Demolition, Water Resistant Compression Performance, Experimental Study And Mechanism Analysis

Detonation velocity and brisance of emulsion explosives influenced by the hydrostatic pressure will decrease in underwater blasting; not only that, sensitivity to initiation and sensitivity to pass of explosives will also decrease, because explosive density will increase by influence of the hydrostatic pressure. Emulsion explosives are widely used for underwater blasting in recent years, so research of water resistance and compression resistance of emulsion explosives in deep water will have directive function for underwater blasting and development of emulsion explosives. It troubles scientific workers that to what extent to descend for explosion capability of emulsion explosives, which of test methods to take, how to improve their water resistance and compression resistance.Emulsion explosives have excellent recovery effect under static pressure and thus we should test capability of emulsion explosives under deep water pressure in which means and methods for dynamic pressure will not be copied simply. Environment of deep water charge is simulated by change of standing water surface pressure which provides feasibility to study compression resistance and water resistance of emulsion explosives in laboratory. According to the principle we mentioned above, five pieces of water resistant experimental equipment and compression resistant experimental equipments were devised, which were all fully adaptable to the experiments. This study used detonation velocity, brisance and the fractal dimension of mortar test block to calculate fallen extent of explosion capability of emulsion explosives due to immersion and Compression, to return to between 0 and 1, to describe water resistance and compression resistance quantificationally, and no longer to confine to the "full blasting", "semi-blasting", "no-blasting" or qualitative description of blasting debris. this research mainly focused on how compression resistance of emulsion explosives is influenced by sensitizing agent types and content, emulsifier types and content, types of the oil material and so on, and how water resistance of emulsion explosives is influenced by the sensitizing agent types, soaking time, and soaking pressure. two one-time experimental equipments which were used to measure detonation velocity and brisance of emulsion explosives influenced by hydrostatic pressure respectively both used PVC material which can reduce experimental material and environment destruction of the experimental equipment; reusable experimental equipment which was used to measure brisance of emulsion explosives influenced by hydrostatic pressure which was designed by the principle of minimum seam so the ingenious design can be kept reusable and safe. Through micro-explosive device and mortar test block,,and to use of fractal theory to deal with data processing, the new method of compression resistance was proposed; the important experimental phenomena were analyzed in deply and systematically.The main conclusions are as follows:emulsion explosives sensitized by glass micro-balloons, by bubbling agent, and by expanded pearlites all have excellent water resistance; water resistance of emulsion explosives is not the main reason for decreased performance of Emulsion Explosives in underwater blasting; Emulsion explosives have excellent recovery ability when effected by the static pressure, and we should test capability of emulsion explosives under deep water;under certain emulsification process conditions:when emulsion explosives contain sodium nitrite content of 0.2%, perlites content of 5% to 6%, and the glass microspheres content of 2% to 3%, compression resistance and explosive properties are both relatively excellent, and compression resistance is influenced by compound sensitizing agent intricately; under certain emulsification process conditions:when emulsion explosives contain T155 emulsifier content of 2%, Span-80 emulsifier content of 3% to 4%, compression resistance and explosive properties are both relatively excellent, and explosives which contain compound emulsifiers have excellent compression resistance; types of the oil material have a little effect on compression resistance of emulsion explosives, and oxidant species and water content have little effect.This main theory achievements are as follows:In the deep water pressure for a long time, fall explosion capability of emulsion explosives sensitized by bubbling agent are mainly because of hotspot reductions in result from infiltration swelling and escape of bubbles; fall explosion capability of emulsion explosives sensitized by expanded pearlites are mainly because of hotspot reductions in result from infiltration swelling and fragmentation and invalidation of pearlites; fall explosion capability of emulsion explosives sensitized glass micro-balloons are mainly because of hotspot reductions in result from infiltration swellingln the certain pressure, fall extent of explosion capability of emulsion explosives sensitized by bubbling agent and emulsion explosives sensitized by expanded pearlites are both great; for the former, the main reason is that sensitized bubbles shrink and explosive density increases excessively; for the latter, the main reason is that hotspots in unit volume is reversely little and explosive density increases excessively. In the same condition, fall extent of explosion capability of emulsion explosives sensitized by glass micro-balloons is not great; the main reason is that hotspots in unit volume is reversely much although the explosive density also increases.