Research On Transmission Property Of Shock Wave Test Underwater Explosion

The damage of structures underwater explosion mainly represents for the effects of shock wave and bubble impulse. Generally speaking, bubble pulse is usually an additional damaging effect, while shock wave plays a decisive role. The propagation law and dynamic effect of shock wave underwater explosion is an important question concerned in hydraulic and hydro-power engineeri,diploma in marine engineering and explosive engineering, which is related to the safety of facilities underwater and the parameters of structure demolished in a blasting reasonable choose,so it is of great value in project and significance in theory.Based on studying effects of shock wave underwater explosion, the trial of shock wave underwater explosion has been carried out in limited water area of steel tank in this paper. First of all, through on-site tests and its phenomenological analysis, the principle of detonator laid were obtained; Secondly, it reproduced the dynamics propagation progress of shock wave underwater explosion by High-speed photography,and drew the propagation speed and their propagation law of water front; According to propagation velocity of shock wave front, Peak pressure in different distances has been educed,and by analysing the relation of peak pressure, dosage and propagation distance, the empiric formula of computation on peak pressure shock wave underwater explosion in little dosage has been obtained.Finally, the engineering examples selected about water pressure blasting were used to verify the results of test,and explain the rationality and practicability of the layout principle. The conclusions can be drawn as follows:(1) Observing the propagation process of shock wave underwater explosion and testing peak pressure are feasible by using High-speed photography;(2) when the experimental conditions are certain, the propagation velocity of shock wave front underwater explosion increases rapidly from zero to a value, then sharply attenuates in waves, ultimately tends to a constant value;(3) The larger the dosage, the faster the propagation speed of shock wave front rises and decays, and the peak pressure of second-wave is greater in identical experimental conditions;(4) According to the relationship of shock wave front between the parameters of water dynamics, the value of peak pressure corresponding to the propagation speed of wave front has been educed,and by analysing the relation of peak pressure, dosage and propagation distance, the empiric formula of computation on peak pressure shock wave underwater explosion in little dosage has been obtained, which is Pm=105.472 (Q1/3/R)1.65 when the ratio of the radius r/r0 is greater than 5.649; (5) In the project of water pressure blasting, for the open-style container-like structures, in order to improve the efficiency of explosive energy and reduce energy consumption, it requires that the depth of detonator into the water is greater than the distance from a container wall to the center of the explosion at least;(6) The position where the detonator is requires to make shock wave front reaching at the wall of container-shaped structure at one time so that it is well-proportioned by force;(7) To reduce energy loss caused by free surface, the open vessel-like structures maybe be filled with water and do closures when conditions are suitable.