Design and validation of blast non-propagation wall for multi-compartmented explosive storage structure of capacity 5 T NEC per compartment

Abstract

Conventional magazines for mass explosion hazard (hazard division 1.1) are constructed using bricks and reinforced cement concrete. For such magazines, magazine inter separation distance or storage inside quantity distance (SIQD) is 2.4 W1/3 m, where W is net explosive content in kg. New composite material called laced reinforced concrete (LRC) has been developed recently, for which the SIQD has been reduced upto 0.5 W1/3 m. Due to substantial reduction in inter magazine separation distances, the requirement of storage land area has been reduced significantly. Although SIQD has been reduced drastically due to development of the new composite LRC, the other quantity distances like process inside quantity distance (PIQD) and outside quantity distance (OQD) reduced marginally. To reduce these quantity distances, one solution is multi-compartmented structures based on Unit Risk Principle. The application of unit risk principle enables the separation of explosives into compartments in such a manner that initiation of explosives in one compartment does not result in initiation of explosives in adjacent compartments. This is achieved by special design of explosive storage buildings incorporating blast non-propagation wall between adjacent compartments storing explosives. Quantity distances are reduced for such magazines because maximum credible limit corresponds to the quantity of explosive in one compartment. Present paper describes design and full scale testing of blast non-propagation wall to be constructed between two adjacent compartments of a multi-compartmented explosive storage structure with storage capacity of 5 T net explosive content of HD 1.1 per compartment. The blast non-propagation wall comprising of sand filling and air gap between LRC walls has been designed for desired attenuation of blast parameters as well as for arresting high velocity fragments/debris. The design has been validated by fully instrumented design validation field trial. The conduct of the trial as well as the trial results one discussed.