抄録
A "blast-wave trap " in an L-shaped tunnel section was studied to mitigate blast pressure outside an underground or subsurface magazine. Small-scale blast measurement experiments, utilizing a square tube model and a 100-mg test explosive, were conducted to evaluate how the trap length, without cushioning materials, affects the waveform and blast pressure parameters outside the tube. When the trap was long enough, the blast wave outside the tube formed a two-wave structure, and the peak overpressure was mitigated significantly. Even with the two-wave structure outside, the waveform near the tube exit inside did not clearly show two wave structures; the second wave steepened rapidly after leaving the tube. The trap’s effect on mitigating blast pressure was assessed by "without trap equivalency," setting the case without the trap as 1. Under the experimental conditions with a two-wave structure outside, the equivalencies based on peak overpressure were approximately 0.2 to 0.4, and those from the positive scaled impulse were approximately 0.7 to 0.9. Installing a sufficiently long trap effectively mitigated blast pressure outside the tube.
