Beirut explosion: TNT equivalence from the fireball evolution in the first 170 milliseconds

The evolution of the fireball resulting from the August 2020 Beirut explosion is traced using amateur videos taken during the first 400 ms after the detonation. Thirty-nine frames separated by 16.66–33.33 ms are extracted from six different videos located precisely on the map. Time evolution of the shock wave radius is traced by the fireball at consecutive time moments until about $$ t \approx 170$$ t ≈ 170 ms and a distance $$ d \approx 128$$ d ≈ 128 m. Pixel scales for the videos are calibrated by de-projecting the existing grain silos building, for which accurate as-built drawings are available, using the length, the width, and the height and by defining the line-of-sight incident angles. In the distance range $$ d \approx $$ d ≈ 60–128 m from the explosion center, the evolution of the fireball follows the Sedov–Taylor model with spherical geometry and an almost instantaneous energy release. This model is used to derive the energy available to drive the shock front at early times. Additionally, a drag model is fitted to the fireball evolution until its stopping at a time $$ t \approx 500$$ t ≈ 500 ms at a distance $$d \approx 145\pm 5$$ d ≈ 145 ± 5 m. Using the derived TNT equivalent yield, the scaled stopping distance reached by the fireball and the shock wave-fireball detachment epoch within which the fireball is used to measure the shock wave are in excellent agreement with other experimental data. A total TNT equivalence of $$ 200\pm 80\,\mathrm{t}$$ 200 ± 80 t at a distance $$ d \approx 130$$ d ≈ 130 m is found. Finally, the dimensions of the crater size taken from a hydrographic survey conducted 6 days after the explosion are scaled with the known correlation equations yielding a close range of results. A recent published article by Dewey (Shock Waves 31:95–99, 2021) shows that the Beirut explosion TNT equivalence is an increasing function of distance. The results of the current paper are quantitatively in excellent agreement with this finding. These results present an argument that the actual mass of ammonium nitrate that contributed to the detonation is much less than the quantity that was officially claimed available.

Studies on Some of the Improvised Energetic Materials (IEMs): Detonation, Blast Impulse and TNT Equivalence Parameters

This work reports the computational analysis of the physicochemical, detonation, blast peak over pressure, blast impulse and TNT equivalence parameters of some of the Improvised Energetic Materials (IEMs) such as ammonium nitrate, urea nitrate, C4, hexamethylene triperoxide diamine (HMTD) and triacetone triperoxide (TATP), which are used in bombing incidents all over the world in the form of Vehicle-Borne Improvised Explosive Devices (VBIEDs) or Person-Borne Improvised Explosive Devices (PBIEDs). The blast impulse, peak over pressure, TNT equivalence and detonation parameters reported in this manuscript will be useful to assess the threat quotient caused by these IEMs, of great help for the energetic materials researchers, technologists and scientists to undertake further research work in the field and for the security agencies to understand the severity of the damage during explosion This paper also accounts for the available detection technologies to fabricate an explosive detection device for its effective identification and detection.

EDS Containment Vessel TNT Equivalence Testing

The V26 containment vessel was procured by the Project Manager, Non-Stockpile Chemical Materiel (PMNSCM) for use on the Phase-2 Explosive Destruction Systems. It was fabricated under Code Case 2564 of the ASME Boiler and Pressure Vessel Code, which provides rules for the design of impulsively loaded vessels [1]. The explosive rating for the vessel, based on the Code Case, is nine (9) pounds TNT-equivalent for up to 637 detonations. This report documents the results of tests that were performed on the vessel at Sandia National Laboratories to qualify the vessel for explosive use [2]. Three of these explosive tests consisted of: (1) 9lbs bare charge of Composition C-4 (equivalent to 11.25lbs TNT); (2) a 7.2lbs bare charge of Composition C-4 (equivalent to 9lbs TNT); (3) a bare charge of 9lbs cast TNT. The results of these tests are compared in order to provide an understanding of how varying charge size affects vessel response when the ratio of free volume to charge volume is small, and in making direct comparisons between TNT and Composition C-4 for TNT equivalency calculations. In a previous paper [3], the 7.2lbs bare charge of Composition C-4, (2) above, was compared to 7.2lbs of Composition C-4 distributed into 6 charges.

Residual Axial Capacity of Reinforced Concrete Columns Subject to Internal Building Detonations

This paper details the development of an engineering assessment procedure for reinforced concrete (RC) column failure when subjected to time-variant coupled axial and lateral loads due to internal building detonations. This is based on a comprehensive parametric study conducted using an advanced uncoupled Euler–Lagrange numerical modeling; splitting the structural and flow solvers for maximum integrity and accuracy. The column assessment charts discussed in this paper provide threshold combinations of TNT equivalence and stand-off distance for a range of column residual axial capacity levels corresponding to two key internal blast environments: Vented and contained. This will be of direct relevance to both practitioners and researchers involved with protective design of civilian and military buildings.

Study on Evaluation of Explosion Effects of Gas Injection Wells

In this paper, blast effect of oil-associated gas in gas injection wells is determined when using air injection displacement, and on this basis, the relevant safety distance is determined also. Numerical simulation is used to calculate the overpressure distribution, explosion energy and TNT equivalence of combustible gas explosion in gas injection wells. Based on shock wave damage criterion, the safety distances in seven levels are obtained, which are personnel minor injuries, severe injuries, death, and destruction of buildings with mild, moderate, severe manage and destroying. Therefore, technical support is provided to accident prevention, emergency and rescue.