The reliability problems of shock tube initiation systems have been a focus in mining and demolition blasting. Current blasting practices widely use shock tubes as a non-electrical initiation means. Shock tube initiation systems typically consist of shock tubes coupled with a donor detonator. Shock tubes are used to transmit an initiation impulse to the target detonators. The shock tubes are initiated and detonated by the adiabatical pressing of the mixture of explosive material and air due to the explosion shock by detonators.
Reliability is the most important for any initiation system, and efficient initiation of shock tubes is an important factor.
There has been some research on initiating a bunch of shock tubes so far. However, all the researchers have concentrated on the experimental study of lateral coupling mode.
Choe Yong Chol, a researcher at the Faculty of Mining Engineering, numerically investigated the influence of coupling modes on the explosion shocks and their propagation to shock tubes, and validated it through the test results of the initiation reliability of shock tubes in bunch.
He used lateral and frontal bunch-series coupling modes for the numerical simulations and tests.
The results showed that the peak pressures of explosion shock acting on the inside of shock tubes, and initiation rates were higher for frontal bunch-series coupling mode than for lateral mode, and that the peak pressures acting on the inside of shock tubes by numerical analysis were in good relation with the initiation rate of shock tubes in bunch by tests.