[en] Short communication

[en] A method was formulated for studying the probability of failure of structures when subjected to repeated blast loads. It was applied to the analysis of a structure subjected to a series of identical blast loads and several different ranges from ground zero. Results indicate that even as few as three repeated blast loads can significantly increase the probability of failure even for cases with a relatively high R/F. (The R/F ratio can be looked at as indicating the relative strength of the structure or as an indication of its range from the point of detonation)

No abstract available

[en] The work reported here is a part of a study to upgrade existing shelters in key worker and host areas. Objective is to determine closures suitable for shelters in these two areas. Ultimate failure of closures (breakout) was determined by dynamic loading tests performed at the BRL 2.44 m blast simulator. Test results are given for three types of closures. Load ratios of ultimate failure to allowable static design loads were found dynamically to be about four for the wood beam/plywood skin closures. This would make it acceptable for both host and key worker shelter areas

[en] This report summarizes the proceedings of a Federal Emergency Management Agency-sponsored Conference on fire and the related effects of nuclear explosions (with passing attention to earthquakes and other nonnuclear mishaps). This conference, the fifth of an annual series (formally called Blast/Fire Interaction Conferences), was held during the week of April 25, 1982, again at Asilomar, California

[en] The blast-wave flows both outside and inside a power house of a nuclear-power generating station, from an accidental explosion of an explosive like TNT or its equivalent during transportation past the power house by a train, are studied numerically and assessed with an appropriate model. Detailed descriptions of both the prediction model and numerical method of solution are given, as well as an interpretation of numerical results. The blast-wave flow into the power house through blow-out panels in the front wall is investigated, including the resulting flow inside the power house that travels through the turbine hall, through the turbine auxiliary bay, over the reactivity deck, through the reactor building, and, in some cases, down through a hoistway to three small rooms on the next lower level. Breaking blow-out panels in the rear wall of the power house and their effects on the internal blast-wave flow is also investigated. Two different flow paths are considered, one through an upper level of the power house and another through a lower level. Finally, the blast-wave flow over the outside of the power house is studied, with an approximate model, so that the pressure differences from the blast wave between the inside and outside of the roof, side walls, front wall, and rear wall can be determined and the resultant blast-wave loading on the building walls thereby obtained

[en] This paper briefly reviews the state-of-the-art of predicting the incipient collapse of structures subjected to blast loads and presents a suggested experimental and analytic, probability-based program capable of producing the required data and criteria by the use of full-scale tests and model studies. Emphasis of this review is on reinforced concrete structures. 45 references

[en] Vapor Cloud Explosions(VCEs) are serious hazards in refining and petrochemical industries. Until now, several empirical models have been proposed to access the damage due to the explosions. An analytical solution of a spherical blast waves due to violent explosion by TNT or any other explosives was obtained by solving the Euler equations in this study. Our calculation results are in good agreement with the results by Multi-Energy method, a well known empirical model. The results may be applied to evaluating the damages due to the explosion

[en] A quasi-one-dimensional computational technique is used to model the flow of a large, complicated shock tube. The shock tube, or Large Blast Simulator, is used to simulate conventional or nuclear explosions by shaping the pressure history. Results from computations show favorable agreement when compared with data taken in the facility at Gramat, France. Such future shock tubes will include a thermal irradiation capability to better simulate a nuclear event. The computations point to the need for venting of the combustion products since the pressure history will be considerably altered as the shock propagates through these hot gases

[en] The growing threats and terrorist activities in recent years have urged the need for rapid and accurate forensic investigation on post-blast samples. The analysis of explosives and their degradation products in soils are important to enable forensic scientist to identify the explosives used in the bombing and establish possible links to their likely origin. Anions of interest for post-blast identification of low explosives were detected and identified using ion chromatography (IC). IC separations of five anions (Cl^-, NO₂^-, NO₃^-, SO₄^2-, SCN^-) employed a Metrosep Anion Dual 2 column with carbonate eluent. The anions were separated within 17 minutes. Sampling of post blast residues was carried out in Rompin, Pahang. The post-blast explosive residues were extracted from soil samples collected at the seat of three simulated explosion points. The homemade explosives comprised of black powder of various amounts (100 g, 150 g and 200 g) packed in small plastic sauce bottles. In black powder standard, three anions (Cl^-, NO₃^-, SO₄^2-) were identified. However, low amounts of nitrite (NO₂^-) were found present in post-blast soil samples. The amounts of anions were generally found to be decreased with decreasing amount of black powder explosive used. The anions analysis was indicative that nitrates were being used as one of the black powder explosive ingredients. (author)