Experimental and numerical investigation of a hollow cylindrical water barrier against internal blast loading

A promising potential method of mitigating the blast effects caused by terrorist explosions is constructing a water barrier encircling an explosive found in public places. Eight in situ experiments were carried out to investigate the response and mitigation efficiency of hollow cylindrical water barriers against internal blast loading. Both the peak overpressure and the impulse along the side toward the base of the barrier were reduced mainly through reflection and diffraction of the blast wave. Numerical models corresponding to the experiments were developed using the commercial software AUTODYN and validated by the overpressure-time histories recorded in the experiments. The numerical results demonstrated that the water barrier enhanced the blast loading over the barrier, although it mitigated the blast loading along the side toward the base of the barrier. Parametric studies were carried out to comprehensively investigate the influences of the thickness, the height, and the inner diameter of the water barrier on the blast mitigation or blast enhancement effects. Adding a water cover on the top of the barrier was proved to be an effective way to eliminate the blast enhancement effects and efficiently improve the blast mitigation performance since it can substantially increase the kinetic energy extracted by the water barrier.