Influence Of Wave-shaper On In-hole Gap Distance Of Sympathetic Denotation

There have been some successful cases in the smooth blasting of the peripheral hole using the conventional diameter uncoupling charge with the axially uncoupled charge of the air-spaced charge detonation initiation method,which has great potential in simplifying the smooth blasting process and reducing the blasting cost,etc.However,due to the insufficient depth of related research work and doubts about the reliability of the process,its popularization and application are greatly limited.This paper is based on the technology that the large wave-shape in the charge structure can modulate the detonation wave waveform and make it interact on the charge axis to generate regular reflection or irregular reflection(Mach reflection),and the detonation parameter is much higher than the normal CJ value.Features.A new way to improve the blasting performance and reliability of the segmented air-spaced charge in the hole by adopting a wave-shape charge structure with in the peripheral holes of smooth blasting was explored.In the simulated explosion test of the steel pipe,based on Explosive-Determination of brisance——Lead cylinder compression test(GB/T 12440-1990)and combined with the measurement of the witness lead cylinder compression value,in-hole gap distance of sympathetic detonation,the relative brisance(witness lead cylinder compression value/standard lead cylinder compression value)are used to comprehensively evaluate the detonation performance and reliability in the hole;At the same time,using the combination of numerical simulation and theoretical analysis,the propagation law of detonation wave and explosive initiation mechanism in the wave-shaper charge structure are studied;Finally,based on the explosive hot spot initiation theory,the dynamic finite element software is used and the orthogonal optimization design method is used to calculate the influence factors of the wave-shaper structural parameters on the martyrdom effect of explosives,and finally the diaphragm parameters with better martyrdom effect are obtained.The main research achievements are as follows:The main research results obtained are as follows:(1)The numerical simulation results of the explosion process in the steel pipe with or without the wave-shaper charge structure are consistent with the theoretical analysis results:in the ordinary charge structure,the detonation point of the blasted explosive occurs at the periphery of the detonation end face of the explosive;The initiation point of the wave-shaper charge structure occurs at the center of the detonation end face of the explosive;Under the same air separation distance,the wave-shaper increases the pressure of the shock wave at the coaxial point of the charge axis by modulating the detonation wave.Stable detonation.The wave-shaper charge structure is easier to form stable detonation than the ordinary charge structure.(2)In the steel pipe sympathetic explosion experiment,based on the lead cylinder compression value in Explosive-Determination of brisance——Lead cylinder compression test,it is proposed to take the "relative stiffness value"(witness lead cylinder compression value/standard lead cylinder compression value)as the judgment standard for the sympathetic explosion results of the delivered charge under the condition of different air spacing distance of different charge structures,and in-hole gap distance of sympathetic detonation of different charge structures is obtained:The in-hole gap distance of sympathetic detonation of the wave-shaper charge structure is 105cm,and the in-hole gap distance of sympathetic detonation of the ordinary charge structure is 80cm(3)Using the dynamic finite element software and based on the explosive hot spot initiation theory,through the orthogonal optimization design method,the structural parameters and materials of the wave-shaper with better detonation effect are obtained.The results show that nylon can ensure the stability of detonation wave propagation better than other materials;The primary and secondary relationships of various factors affecting the in-hole sympathetic detonation effect of the wave-shaper charge structure are:the wave-shaper diameter and the wave-shaper thickness.The structural parameters of the wave-shaper are:diameter 0.8D(D is the diameter of the explosive)and thickness 2.5cm.